Following scenario happened to me earlier: Enemy ducks a cone of cold. Enemy casts cone of cold on my wizard. Wizard has no other status effects. My priest purges the cone of cold. The cone of cold is not purged. Is this working as intended or a bug? If its working as intended, this would make duck a stronger ability as one could duck abilities, cast them on an enemy, and they would get full duration unless knocked off. I understand that technically the cone of cold was "mine", but the system is flagging the debuff as one that I myself had cast on myself due to the card originally having been mine. This raises another issue: If a dwarven priest ducks a beneficial ability - let's say inspiring presence from an enemy priest. This dwarven priest has altruism. Let's say the dwarven priest casts inspiring presence on two allies. Would this have the same effect as being seen as enemy card and not proccing altruism?
This bug has been around for a while (not sure why it hasn't been fixed yet). Did you try moving after the purge? In my experience with the bug, the card appears to stay on the character, although it is actually no longer affecting them. I think the game does consider the owner of the stolen card to be the one who stole it, however there is a graphical error where purging a stolen card doesn't actually remove it.
My immediate thought is No. Altruism triggers on when you play a Holy card targeting an ally; and Inspiring presence would target any characters in range, including allies. Now, if Inspiring Presence (or another card that was Duck'd like Healing Rays) only targeted allies, it will target the caster's allies since the caster has played it and they are his allies. Purge is just programmed to detect whose deck the card originated from, and nothing else. It's an interesting bug.
Another interesting issue is that: If I really am not coc'ed or frozen in some capacity, yet I have the debuff icon, do I have only 2 statuses with one being a phantom debuff icon? Or do I have 3 statuses after the purge, but one of them is broken? Either way, this could impact my available buffs if I had 2 buffs, then was frozen for a total of 3 statuses, and a new status is applied, knocking off 1 status (as if I had 4 statuses) when in reality I should have the 2 priors and the one new one.
On a related note, if you have someone else's card, and discard it, it will say <original owner> discarded the card instead of the current holder.