Four on the floor

[BillyMac]

Originally Posted by Adam

The T is for not having the players all return from a TO at approximately the same time. It's generally not called unless the last returning player gains an advantage by the play.

10.1.9 SITUATION: Following a charged time-out Team B is still with their
coach on the sideline when the official sounds the whistle to indicate play will
resume. Four players of B return to the court just in time to play defense as A1
attempts an unsuccessful three-pointer. B1 rebounds and throws a long pass to
B5 who enters the court just in time to catch the pass. RULING: A technical foul
is immediately charged to Team B for failing to have all players return to the court
at approximately the same time following a time-out or intermission. While it is
true the entire team may be off the court while the procedure is being used, once
a team responds, all players must enter the court at approximately the same time.

What if B5 returns at a time when no obvious advantage is gained? He just walks onto the court and joins his four teammates, either during a live ball, or during dead ball, and is observed by an official walking onto the court. Citation please.