Play situation - Need input.

Hey guys I was at a game last night and this situation came up during pregame. A1 dribbling lenght of floor with defensive pressure, assume B1 between A1 and basket so A1 can't make move toward basket. A1 continues to dribble toward baseline, when A1 reaches baseline they jump into the air over out of bounds and throws pass across the floor to the corner to A2 who has an open shot. Is this legal or do you have a violation and what violation would it be?

I have an idea what I would do but I want to get everyones thoughts on this as there are 2 different thoughts on this play between the guys I talked with and their previous partners who originally brought this play up.