I am unaware of anything in Scripture that even remotely forces one to choose between who sends the Holy Spirit, Father or Son!

It can surely be either one or both since Jesus declared that, "I and the Father are one" (John 10:30) which must mean, among other things, that they act in concert, concord, collaboration.

Thus, we find that:
 - Jesus sends the Holt Spirit, Luke 24:49, John 15:26, 16:6; Thus, the Holy Spirit is also called, "The Spirit of Christ", Rom 8:9, Phil 1:19, 1 Peter 1:11
 - the Father sends the Holy Spirit, Rev 5:6, John 14:26; Thus, the Holy Spirit is called the Spirit of God, Matt 3:16, 12:28, Rom 8:9, 14, 15:19, 1 Cor 2:11, 14, etc.
 - the Holy Spirit is sent from heaven, 1 Peter 1:12.

Thus very idea of the Holy Spirit being BOTH the Spirit of Christ and the Father is testament to the closeness of these three great persons.  Recall that, 

John 16:13, 14 - However, when **He** the Spirit of truth comes, **He** will guide you into all truth. For **He** will not speak on His own, but **He** will speak what **He** hears, and **He** will declare to you what is to come. **He** will glorify Me [Jesus] by taking from what is Mine [Jesus'] and disclosing it to you.