Simultaneous charge and block

[just another ref]

Originally Posted by BktBallRef

Because the case play says so.

Actually it doesn't. The word signal does not appear in the case play.
But following this line of reasoning, here is a question. Has anyone here ever reported a double foul when only one official made the preliminary block/charge signal and the other went up with just the fist and waited?

You think to yourself: Oh, my gosh! He called what?? Nothing to do but salvage a split.

Or in this case is it acceptable for the official who did not make the signal to provide information to the official that made one (He cleared out with his inside arm, etc.) and allow him to change his call?