Until what point can you no longer call...?
 

... a free throw violation?

Team A has 3 teammates (A2, A3, & A4) of the thrower lined up in marked lane spaces.
Officials don't recognize. A1 is shooting two free-throws.

Ball is at disposal of thrower.
Thrower shoots free-throw. Ball goes in.
Official takes ball out of the basket.

Say substitutes are coming in. Officials notice A4 leaving the top lane space (maybe even gets substituted for). Official begins puzzling. Team A is now legal, no 3rd teammate in a marked lane space.
Lead announces: "One" and bounces ball to thrower.

Ball is at disposal of thrower.
Ball is thrown by the thrower.
Ball goes in.
Team B takes ball for endline throw-in.
Team B's legal throw in ends.

My question is this: at what point (exactly) can you no longer call the free-throw violation on Team A? Say our puzzling official finally figures out that a violation on Team A DID occur on the first free-throw (which was made). When does the ability to call and enforce the violation end?

You have to notice it while it's being committed. Once the ball becomes dead, there is no longer a violation.
You have until the try ends, basically.

After the shot goes through it's to late to correct.

Posted on another thread:

Noticed before the ball is at the disposal of the thrower -- fix it.

Noticed before the FT ends -- violation.

Noticed after the FT ends -- too late to do anything.

And I Mean Always ...
 

Always listen to bob.