Scenario from Adv. Camp

[Big Slick]

Originally Posted by MrRabbit

Yes it is...

In this case, it doesn't matter. With a runner on first, if you enforce both penalties:
IP - R1 to second, ball on BR, THEN Catcher's obstruction: BR to first, R1 doesn't advance (not forced). The effect is the same as if you just enforced the catcher's obstruction (BR to first, R1 forced to second).

The fun would be if R1 is at second and BR retired at first. Now the two effects would be different. My take is that you have to enforce both - R1 to third on the IP and BR to first on the Catcher's obstruction.
(ASA has a similar case play in which both penalties are enforced: IP and HPB.)