Delayed violations signal

[crazy voyager]

I've been thinking (and now I'm talking FIBA mechanics)

Why don't we have a signal for delayed violations? This would mainly be free throw violations and goal-tending.

I'm thinking something like this, fast break A1 goes up for the lay up with B1 right behind, B1 comes so far behind he hits the net (interfering with the basket) while the ball is on it's way down; this is a violatoin, but you don't have to call the play dead unless the shot misses, so why dont' we have a sign to show saying "a violation might be called here"?

Same thing happens on free throw violations (fiba don't use the clenched fist sign).

What do you think? possible signs could be the NCAA player control (hand on neck) or hand on the head (NBA 24 second),or you could simply show the violation sign without blowing the whistle

Any thoughts?