For NCAA, the ruling regarding a ball that becomes dead behind either goal line is determined by the impetus that caused the ball to be behind the goal line when it became dead. Things that provide impetus are: batting (legal or illegal) of a loose ball after it strikes the ground, kicking (legal or illegal), a backward pass (including the snap), a fumble, or contacting a live ball that has come to complete rest. No other contact with the ball creates impetus on the ball. To be very clear, a MUFF of a ball NEVER creates impetus. NEVER. A muff of a loose ball in motion does not impart impetus on the ball. The impetus remains with whatever caused the loose ball to be in motion.
Any time the ball is legally kicked, that kick provides impetus, if the ball becomes dead behind a goal line, and nothing else happened that would have provided the impetus.
For example, when a legally kicked ball (still in motion) is muffed by a player of either team, and the ball then becomes dead behind a goal, the impetus is from the kick, not the muff. If that ball becomes dead behind A’s goal line, the result is a SAFETY, because the impetus is from the kick, and the kick was made by Team A. You may wonder how that might happen. Yes, it would be rare, but a blocked, or simply a bad, kick made near Team A’s goal line might land within ten yards or so of that goal line, and deflect off of a helmet or shoulder pad, and bound into A’s end zone, where Team A recovers it and the ball becomes dead (the recovering player gets tackled there, or the ball had crossed the NZ as/before it was muffed, and the ball becomes dead because Team A can’t advance a legally kicked ball that has crossed the NZ).
Some folks may not think it is fair for this to be a safety, if it was muffed by Team B, especially if the ball had crossed the NZ. It may, or may not, be fair. Not for us to debate. By current rule, that is a safety, in NCAA football.
So those of you that also work other rule sets, be sure you know this may be different in other rule sets.
