I'd like to report another bug. I may be experiencing this one on my own. When Player unlimited health is active some of the zombies are either invincible or really hard to kill. I've seen a zombie with no legs, arms, or a head floating around trying to attack me. Also, the zombies affected by this either count as more than one kill or give me PP more than once. I believe this is from the game thinking I am killing it but since it is invincible It'll count as another kill if I attack it enough.
Thats normal you'll also get unlimited health for some bosses you need to kill. I actually don't play with that one on but you can try just shutting it killing the thing then putting it back on you should be fine. Also I believe you can simply press it when your low on health it should give you full health then you can simply shut it off, use it sort of as a refill health option.
Dont know if you had your other question asked about it sounding like he was breathing heavy, just re-download the trainer its updated and it fixed that issue.