I will attempt to get the Board back to discussing football, if that is possible.
I found the case play below in my off season study.
6.3.1 SITUATION A:
A scrimmage kick by K1 comes to rest on R's 6-yard line. R1 attempts to recover and advance, but muffs the ball so that it rolls into the end zone where:
(a) R2 downs the ball; or
(b) R3 recovers and advances out of the end zone; or
(c) K2 recovers and downs the ball in the end zone.
RULING: The ball became dead as soon as it broke the plane of R's goal line. It is a touchback in (a), (b) and (c). The kick had not ended because muffing does not constitute possession, therefore, it is a kick into R's end zone which is an automatic touchback. The covering official should sound the whistle immediately when the ball becomes dead as a result of breaking the goal-line plane. Force is not a factor on kicks going into R's end zone. R will put the ball in play, first and 10, from their 20-yard line. (2-24-2, 8-5-3a)
The above case states this is a touchback.
By definition this is still a kick, but 2-13-1 states a new force can be added to a grounded kick by a muff.
Since the ball is at rest when it is muffed, what is the rationale for the muff not being a new force?