Love kick plays....

[Welpe]

Good question. It is not a touch back because it was not a kick that crossed the goal line. Once the R player possessed the kick, it was no longer a kick and instead became a running play.

Check out the Rule 2 definition of kicks:

2-24 Kicks:

ART. 2 . . . A kick ends when a player gains possession or when the ball becomes dead while not in player possession.

Then look at Rule 6-3-1:

ART. 1 . . . It is a touchback if any free kick or scrimmage kick:
a. Which is not a scoring attempt or which is a grounded three-point fieldgoal
attempt, breaks the plane of R’s goal line, unless R chooses a spot of
first touching by K.