Illegal pitch or no pitch.

[UmpireErnie]

Originally Posted by EsqUmp

Illegal pitch = delayed dead ball.

Runner leaving early = dead ball.

Illegal pitch occurred first. Offense gets the choice of the result of the play or enforcement of the illegal pitch penalty (because not all runners safely advanced).

I assume the offense will take the penalty (ball on batter and runner gets a base).

I don't know why people keep trying to complicate these plays.

At the risk of being one of those "people"

The IP being discussed here is F1 failing to deliver the ball after separating the hands. If R1 leaves early, say after the hands separate but clearly before F1 falls to the ground without releasing the ball then didn't the offensive infraction come first? And since leaving early is immediate dead ball the IP never happens....