1.0.5 heroism infusion not working

[Bonzard]

I was fighting a stealthed orc assassin I got low health hit my heroism infusion, it got me to 200 something health. At this point i saw i still had 6 turns left on my heroism infusion hit the remainder of my 200 something health it did not hit over my -health and just killed me like I did not have it on.

I could not see the stealthed orc by the way.