I had a game once where a team was pressing and the offense threw a hard pass that was deflected straight into the basket, so weird things can and do happen!

I am guessing that in your case it was deflected from inside the 3 point line. The OP case was from outside the 3 point line. I will never, ever, ever see this in a game. But if I see it on some messed up test I'll say score 3 points, provided it didn't hit the floor. 5-2, Thrown ball from the field. If someone can provide a case to show me wrong, please do.

Yeah, just like it's a stretch to consider if a self-pass off the backboard was a shot attempt and subsequent rebound/dunk. :D