Caught Foul Ball off of Equipment

[Fritz]

Was PU today in a 14U league game and got overruled by my partner on a call but can't find a rule to back him up (no argument from either bench).

Sitch: R2, R1, 2 outs, 1-2 count to the batter. Pitch comes in and batter fouls it straight back where it hits the catcher's mask (not his mitt) and bounces up. Catcher wheels around, dives, and makes the catch.

I call the batter out, caught foul ball. My partner, a guy with a number of years more experience than I and someone I respect, comes in calling time. We conference and he tells me that as soon as the ball hit the catcher's mask, it is a dead foul ball and can't be caught. I said "aren't you thinking about a foul tip vs. foul ball?" He says nope, foul ball off of equipment is dead.

So I sell it to the two coaches, they say okay and the kid strikes out swinging on the next pitch anyway.

But I've been going thru both my Fed and ORB books and case studies, and can't find the rule my partner is citing. Did we kick it or get it right?