Would you call this????

[MD Longhorn]

Another of those interpretations that most would likely let go at lower levels. But at varsity, if this guy is on the field, behind the line, when the ball is snapped - it's a penalty. B should have coughed up a timeout if they couldn't get him off in time.

Incidentally, I don't think it's the act of crossing the NZ (unless this is called more strictly in NF than NCAA) that creates the penalty. It's not an immediate penalty (in NCAA) unless he's unabated to the QB. If he gets off the field (or perhaps at least behind that side's LJ or HL) before it's snapped, I think he's fine. (I do believe he has to get back upfield to the players box though --- he couldn't have simply run out of the EZ or straight out of bounds).

Also - some better teams have their centers or QB's (or holders) trained to spot encroachment or 12 on the field, and snap it. If he snaps it specifically to get the penalty, do you still have the same opinion about flagging it?