We have the same problem this year with the definition of "catch" in the rule book and a play interpretation or two in the Case Book. 
REPLY: There has been an inherent problem with the definition of "catch" for many years. According to the definition, you can't have a catch till player possession is established, but according to the definition of player possession, you can't have player possession of a live ball until the player catches it. Huh?? Which is it? The football version of "chicken and egg."
There's a simple way to fix it, though it has been proposed and rejected:
ART. 1 . . . A catch is the act of establishing player
possession control of a live ball which is in flight, and first contacting the ground inbounds while maintaining
possession control of the ball.