T or nothing

[timeout]

White shooting 2 free throws. First one missed, tweet, white now has 3 players come out of the game, but only 2 replacements come out on the floor. Black also has 2 players go off & 2 players come out onto the court. After the subs, administrating official bounces the ball to the white free thrower. She misses, black gets rebound, at this time, white sub (who was on the bench by mistake), now comes onto the court.
T or nothing?

[just another ref]

I believe there is a case play that addresses this which states that if this happens during a substitution involving multiple players and is apparently a result of confusion and no advantage is gained, play on.

[PG_Ref]

This applies if it is not after a timeout or intermission...

Caseplay
10.3.2 SITUATION B:

After a lengthy substitution process involving multiple substitutions for both Team A and Team B, A5 goes to the bench and remains there, mistakenly believing he/she has been replaced. The ball is put in play even though Team A has only four players on the court. Team A is bringing the ball into A's frontcourt when the coach of Team A realizes they have only four players. The coach yells for A5 to return and he/she sprints directly onto the court and catches up with the play.

RULING: No technical foul is charged to A5. A5's return to the court was not deceitful, nor did it provide A5 an unfair positioning advantage on the court.