Surely does not have to have anything to do with a PSCA. Player's leg stamped injured so that he can't play on. There does not need to be either concussion or blood. "Free" replacement allowed. Clearly the ref / officials must have seen the foul play. The team can't "claim" it.
Pegleg, I'm just saying that there might be an opportunity for a team to game the system with this Law. My PSCA scenario was just one just an example of how it might be done.
Here is another.
The SH has been subbed off, and replaced by the back-up SH. Two minutes after coming on, the backup SH is injured and has to go off. The team has no SH now. At the next act of
"personal" foul play, if the victim is a back, be could claim he cannot continue. This would allow the team to bring the starting SH back on when he otherwise would not be allowed back on.
Now, I cannot see this sort of thing happening very often, but in an important match at elite level, I have no doubt that a coach might try it on. After all this is just an extension of what happened in "bloodgate"; Quins used the blood replacement exception and faked a blood injury to bring on a previously subbed player, the goal-kicker IIRC. Who saw "bloodgate" coming?