Two fouls

[WhistlesAndStripes]

A1 releases an try for 3 points. Before returning to the ground, he is fouled by B2. Trail official blows his whistle for the foul. The basket goes in. While the try is in flight, in an attempt to get in position for a rebound, B3 fouls player A2 on the low block near the basket. Lead official blows the whistle for a foul on B3.

What is this situation? Please use rulebook terminology and refer to rules, and explain what penalties, foul shots, etc. should be administered. A is in the double bonus.