Possible Bug involving the prisoner boss fight interacting with sorc djinn minions

It seems like during this fight, the prisoner can leech to full life off invulnerable minions which in and of itself may be intended, but he seems to be able to leech to full off djinn even whe they are not actively spawned in, making the fight impossible if you are specced into djinns. I had to respect out of my djinn skills to make this possible.

I might be wrong on this or missing something, but that seems to be what was going on.