Why did Ahimaaz the son of Zadok run ahead of the Cushite to Only provide good news about War Victory, & Not the Bad News about Absalom's death?

Question

(2 Samuel 18:19-33) (New American Standard Bible 1995 ) 19 Then Ahimaaz the son of Zadok said, “Please let me run and bring the king news that the Lord has freed him from the hand of his enemies.” 20 But Joab said to him, “You are not the man to carry news this day, but you shall carry news another day; however, you shall carry no news today because the king’s son is dead.” 21 Then Joab said to the Cushite, “Go, tell the king what you have seen.” So the Cushite bowed to Joab and ran. 22 Now Ahimaaz the son of Zadok said once more to Joab, “But whatever happens, please let me also run after the Cushite.” And Joab said, “Why would you run, my son, since you will have no reward for going?” 23 “But whatever happens,” he said, “I will run.” So he said to him, “Run.” Then Ahimaaz ran by way of the plain and passed up the Cushite..............................................................................................................more scripture............ more scripture.................................27 The watchman said, “I [b]think the running of the first one is like the running of Ahimaaz the son of Zadok.” And the king said, “This is a good man and comes with good news.” 28 Ahimaaz called and said to the king, “[c]All is well.” And he prostrated himself before the king with his face to the ground. And he said, “Blessed is the Lord your God, who has delivered up the men who lifted their hands against my lord the king.” 29 The king said, “Is it well with the young man Absalom?” And Ahimaaz answered, “When Joab sent the king’s servant, and your servant, I saw a great tumult, but I did Not know what it was.” 30 Then the king said, “Turn aside and stand here.” So he turned aside and stood still. 31 Behold, the Cushite arrived, and the Cushite said, “Let my lord the king receive good news, for the Lord has [d]freed you this day from the hand of all those who rose up against you.” 32 Then the king said to the Cushite, “Is it well with the young man Absalom?” And the Cushite answered, “Let the enemies of my lord the king, and all who rise up against you for evil, be as that young man!” 33 [e]The king was deeply moved and went up to the chamber over the gate and wept. And thus he said as he walked, “O my son Absalom, my son, my son Absalom! Would I had died instead of you, O Absalom, my son, my son!”

I might just be asking the obvious but, Why did Ahimaaz the son of Zadok run ahead of the Cushite to Only provide good news about War Victory, & Not the Bad News about Absalom's death?
( Was Ahimaaz being a sleazy opportunist in the aforementioned scenario? Were there any benefits for Ahimaaz for bringing Only the good message? )

---

Update:

@vincent-wong Thanks for your response, and for referring to

( 2 Samuel 18:29 ) The king said, “Is it well with the young man Absalom?” And Ahimaaz answered, “When Joab sent the king’s servant, and your servant, I saw a great tumult, but I did Not know what it was.”

Therefore, we could probably assume the following about Zadok's son, Ahimaaz, motiviations:

1. Sort of a sleazy opportunist action whereby Ahimaaz wanted to show himself as the messenger of good news regarding the War Victory for King David

2. Based on @vincent-wong referring to the ( 2 Samuel 18:29 ) bible verse, and subsequently ( 2 Samuel 18:32 ) bible verse that indicated the Cushite's confirmation of Absalom's death, Ahimaaz probably wanted to give King David a hint that Joab was in some way associated to the death of Absalom. Ahimaaz probably thought that the Cushite would Only confirm Absalom's death, but would Not even hint that it was Joab. Therefore, Ahimaaz wanted to some how hint that Joab was behind Absalom's death by telling King David that Joab sent him and the Cushite as messenger while there was a "great tumult" in ( 2 Samuel 18:29 ). Ultimately, David would be able to put the pieces of the puzzle together by analzying Ahimaaz told him, and then later on what the Cushite told him. Essentially, David would determine that Joab was the person that caused Absalom's death

3. Probably a combination of 1) and 2) that would suggest Ahimaaz was an opportunist, and also wanted King David to know that Joab was guilty for killing Absalom.

Answer 1

Ahimaaz son of Zadok and Jonathan son of Abiathar were two designated informants David appointed when he escaped from Jerusalem. 2 Samuel 15:27-28 read

27 The king also said to Zadok the priest, “Do you understand? Go back to the city with my blessing. Take your son Ahimaaz with you, and also Abiathar’s son Jonathan. You and Abiathar return with your two sons.

28 I will wait at the fords in the wilderness until word comes from you to inform me.” (NIV)

Bearing with his responsibility, Ahimaaz insisted to take the news to the king that he probably had a secret agenda in his mind.

Here is the question, why did he lie to the king the death of his son Absalom, while he surely knew it as described in 2 Samuel 18:20.

20 “You are not the one to take the news today,” Joab told him. “You may take the news another time, but you must not do so today, because the king’s son is dead.” (NIV)

Let's read carefully how did Ahimaaz answered David, 2 Samuel 18:29

29 The king asked, “Is the young man Absalom safe?”

Ahimaaz answered, “I saw great confusion just as Joab was about to send the king’s servant and me, your servant, but I don’t know what it was.” (NIV)

Ahimaaz run passed the Cushite had the purpose of bringing a key message to the king in advance. In his message, he did not reply directly David's question, but he mentioned it was Joab sent him, which did not required as he himself said he was the king's servant and earlier, he was designated as the informant to David. Later when the Cushite told the king Absalom was dead, David was able to connect Joab was the one who killed his son.

Was Ahimaaz a sneaky person? I think we couldn't conclude that. Joab was an esteemed general who won many battles for the king. Who dared to be the witness? But anyone who smart enough to know the relationship between Joab and David, would know even David knew Joab killed his son, David would not kill Joab but Joab would certainly avenge to the informant.

Ahimaaz knew his ambiguous message was good enough to let David know, but Joab wouldn't notice that he was the informant.

Answer 2

I have a different interpretation; I think Ahimaaz genuinely didn't know that Absalom had died. It was clear that the battle was won as the soldiers all returned to their tents, but I don't think everyone necessarily knew that Absalom was dead. Looking first at the account of Absalom's death and burial in 2Sa18:14-17:

14 Then said Joab, I may not tarry thus with thee. And he took three darts in his hand, and thrust them through the heart of Absalom, while he was yet alive in the midst of the oak. 15 And ten young men that bare Joab's armour compassed about and smote Absalom, and slew him. 16 And Joab blew the trumpet, and the people returned from pursuing after Israel: for Joab held back the people. 17 And they took Absalom, and cast him into a great pit in the wood, and laid a very great heap of stones upon him: and all Israel fled every one to his tent. (KJV)

First, considering Absalom's actual death, the only people who witnessed it were Joab, the ten young men, and anyone who was close by to the tree where he was killed. The last category of men did not account for a large proportion of the army, because Joab had to call the men back with his horn, which happened after Absalom's death.

Considering the burial - the subject of the verb "took" in v17 is unclear: is "they" (which is a pronoun not in the original Hebrew but can be inferred) referring just to Joab and the ten young men (vv14-15) or is it referring to all the army (v16). I think it's just referring to Joab and the ten young men, because you don't need a whole army just to bury someone, and also they were travelling through a wood so it would not be viable with a large number of people.

Given that only a small number of people witnessed Absalom's death and burial, it's reasonable to assume they wanted to keep it that way at least for the time being. Joab was clearly aware that David would not be in a good mood after hearing of Absalom's death (v20), so he probably wanted to manage the situation and not create a panic. It's also respectful to tell someone's father of their death before telling those outside the family.

Note that the Cushite did actually see Absalom dead first hand, as Joab asked him to report what he had "seen" (v21). However Ahimaaz likely didn't see it, as Joab tells him that he (Ahimaaz) has nothing to report:

22 Then said Ahimaaz the son of Zadok yet again to Joab, But howsoever, let me, I pray thee, also run after Cushi. And Joab said, Wherefore wilt thou run, my son, seeing that thou hast no tidings ready? (KJV)

I assume that (in contrast to the Cushite), Ahimaaz had nothing ready to report because he didn't know that Absalom had died.

@VincentWong interprets v20 to mean that Ahimaaz definitely knew of Absalom's death, but I don't necessarily think that's the case, given his behaviour later. It's possible that Ahimaaz simply did not know which son Joab was referring to. David had many sons, some of whom were probably fighting in the battle on the side of David. From Ahimaaz's perspective, he just knew one of David's sons had died - it may have been Absalom, or it may have been another of the sons. Establishing this detail was not important to Ahimaaz at the time he left as he only wanted to tell the king that the battle had been won.