Or more likely; to be able to see the card HIMSELF, calling his OWN BP into the game; and signaling him while standing up (Which BTW was NOT addressed by the Einbinder/Dalben decision; it may very well BE illegal to use such a method to HC). That same Asian team has pulled THIS trick MANY times, including at the table where I was PERSONALLY playing.
Either way; the ethical thing to do if you stumble upon an AP who's in the middle of a play is to simply
leave him alone. You may later want the same "professional courtesy" from him.( If he INVITES you to play, that's another story.)
Bumping heads with another AP can ONLY result in major problems for BOTH parties; as NightStalker has pointed out. I don't know why this is so hard for some people to understand.