[BoomerSooner]

I've had the awful luck of being able to one-up the situation described in the OP. A1 blows by B1 on the dribble and pulls up in front of B2 for a jump shot. B1 still chasing the play can't put on the brakes quickly enough and bumps A1 on the way up and was enough for me to blow the whistle for a foul. B2 had jumped to contest the shot but realizing that A1 now had the opportunity to try for a 3 point play decided he wasn't going to let A1 get a shot off (he was wrong about that) and slashed him across the arm and caught enough of A1's face to draw blood and make me feel it was flagrant and that I couldn't let it go.

I watched the following action with a made 2 point try and then signaled to the coach to attend to the shooter's bleeding nose. On the court to the players, I announced that I had fouls on B1 and B2 and to line up to shoot free throws, and notified my partner that B2's foul was flagrant. Being the lesser experienced ref on the court, my partner gave me a let's talk privately look/head nod (subtle so as to not cause any doubt with the coaches/players/spectators; I loved that guy for all the wisdom he imparted), and he asked me if I was sure I had two fouls. He agreed with my analysis from his vantage point, and I think the question was really whether or not I really wanted to go with a multiple foul and call the second flagrant because I was about to have A shoot 3 FTs instead of 1. He never questioned my judgement, but it was mostly a make sure you're ready for this talk. He recommended announcing it to table then pulling both coaches in to explain the situation. The coaches, even B, understood the call (I think it helped that A1 had a nasty nose bleed). B's coach didn't argue the fouls, but did get a little upset about the penalty enforcement. I assured him that was the right enforcement and other than hand slap to his forehead he walked away just shaking his head. The crowd's reaction was another thing, but otherwise it really wasn't that bad. I've never had anything close enough to call a multiple foul since then, let alone a multiple foul with a flagrant.