Samson's adherence to the Nazirite vow has always been a source of contention. Firstly, let's establish what the rules of the Nazirite vow are according to Numbers 6.
- No eating food made from grapes, dried or fresh.
he shall separate himself from wine and strong drink. He shall drink no vinegar made from wine or strong drink and shall not drink any juice of grapes or eat grapes, fresh or dried. All the days of his separation he shall eat nothing that is produced by the grapevine, not even the seeds or the skins.
- He cannot shave his hair.
all the days of his vow of separation, no razor shall touch his head. Until the time is completed for which he separates himself to the Lord, he shall be holy. He shall let the locks of hair of his head grow long.
- He cannot have any contact with a corpse, not even family.
All the days that he separates himself to the Lord he shall not go near a dead body. Not even for his father or for his mother, for brother or sister, if they die, shall he make himself unclean, because his separation to God is on his head
There's an example of Samson breaking almost all of these vows.
He drinks wine (Judges 14:10), he touches a corpse (Judges 14:8-9) and he has his hair cut off (Judges 16, not willfully, of course). There's not really a reasonable excuse for any of these clear violations of the Nazirite vow. I think it's safe to make the assumption that Samson is a bit of a rebel.
What is interesting is that in Judges 13, when Samson's mother is visited by an angel, the command for Samson not touching corpses is conspicuously left out.
but he said unto me: Behold, thou shalt conceive, and bear a son; and now drink no wine nor strong drink, and eat not any unclean thing; for the child shall be a Nazirite unto God from the womb to the day of his death.'
JPS 1917
It's possible that because the angel predicts Samson will "begin to save Israel out of the hand of the Philistines" (Judges 13:5) that he was somehow exempt from this provision of the Nazirite vow.