Illegal Participation
 

Second down and 10, ball on the 50, pass play. The receiver goes down the sideline steps out on the 30 (not forced out) and re-enters on the 25 (the ball was not in the air on the receivers re-entry if that matters) makes the catch and sprints into the endzone. HL flags the spot where the receiver re-entered the field. Where is the penelty (for illegal participation) administrated from, the spot where he re-entered (25) or the previous spot?

The spot of the foul (where the flag is thrown) is the spot where the receiver comes back in bounds.

As for the penalty: Since it's a loose ball play, the basic spot is the previous spot, therefore the penalty is 15 yards from the previous spot.

This is covered quite well in the rule/case book.

Would it be different if he was forced out?

What if he was being forced out and only 1 step was out of bounds?

Also, why is this not illegal touching instead of illegal participation?

Yes it would be different if he was forced out . HE must return ASAP and there would be no foul..

It is not illegal touchng as he was an eligible receiver. (if he he goes OB on his own and returns he is still eligible)

Definitely previous spot b/c it is a loose ball play. Remember, any action preceding a loose ball is also part of the loose ball play.

What if A runs an option and the half back steps OOB (Not forced) and comes back in to get a hand off from the QB? Now it's a running play, right???

Ok, what if he went out of bounds (not forced), came back in, and did not touch or catch the pass? Is this still a penalty?

In Fed, yes it is. Even if an A or K player goes out of bounds accidently, and comes back in, it is illegal participation.