Suicide Squeeze Catcher's Interference?

 
There are no outs, a left handed batter (B1) at the plate, and a runner is on third base (R3). As the pitcher begins his pitch home, R3 dashes home on a suicide squeeze. The catcher see R3 heading home, so he steps up onto home plate, catches the pitch, and tags R3 out before he reaches home plate. The left handed batter made no movement or attempt to hit the pitch.
 
The offensive coach thinks he saw catcher obstruction/interference since the catcher caught the pitch before the batter had chance to hit it. If true, what does the umpire do with R3 and B1? The defensive coach reminds the umpire that the batter made absolutely no attempt to strike the ball, so the results of the play should stand (R3 out). What does the umpire do now?
 
Call
When the catcher steps on (or across) home plate during a pitch, it is catcher obstruction. In the play below, the catcher obstructed. Any runner attempting to advance on the pitch is awarded that base. The batter is awarded first base -- so R3's run counts and B1 is awarded first base. Check out rule 8-1-1e-1 and 8-3-1c and casebook 8.1.1L.