[stiffler3492]

Originally Posted by BillyMac

An intentional foul is a personal or technical foul which neutralizes
an opponent's obvious advantageous position. Contact away from the ball or
when not making a legitimate attempt to play the ball or a player, specifically
designed to stop or keep the clock from starting, shall be intentional. Intentional
fouls may or may not be premeditated and are not based solely on the severity of
the act. A foul also shall be ruled intentional if while playing the ball a player
causes excessive contact with an opponent.

If B1 was making a legitimate play to try to draw the charge, then it may have just been a blocking foul.

If B1 was just in there to cause contact to make A1 miss the shot, you may have a case for an intentional foul.

If said contact was excessive, then you may have a case for an intentional (hard) foul.

I guess that we all had to be there?

The way I saw it, he wasn't making a legitimate attempt to draw a charge. The part in red is what I think might apply.