Tap situation
 

Gentlemen and women: Team A shoots from just inside the top of the key and catches the back iron at a hard angle resulting in a high, reasonably long rebound (just inside the free throw line, center of the lane). Both A1 and B1 are there awaiting the rebound (you know the look--semi-crouch; heads cocked upwards; eyes glued on the ball) when A2 runs up the lane (from the approx. area the shot was taken), places his right hand on the left shoulder of A1, and skies to tap the ball with his left hand towards the basket for what by all appearances will be a successful tap/try.

Two questions:
1) is there anything to be called in this scenario?
2) if so, whose primary jurisdiction?

Feel free to finish it with whatever appropriate insight can be made.

If there was anything to call, it'd be a technical foul.

Rule 10-3 Player Technical
A player shall not:

Article 6...Commit an unsporting foul. This includes, but is not limited to, acts or conduct such as:

e. Climbing on or lifting a teammate to secure greater height.

Now this is definitely HTBT situation. As to who would have the call, I'd say probably the trail or center would have this call.

unless it's so obvious that Stevie Wonder can see it....I've got nothing. I'm not calling a foul or a T on either A1 or A2 in the play you've described.

Pardon my ignorance--I'm new and not familiar with the common acronyms: what is HTBT?

Had to be there

Like was said previously, unless it's obvious, Id let it go.