[b]This problem was solved and it turns out it was my fault. I'm going to leave this up in case it helps anyone else out. The solution is in the comments.[/b] Not sure if anyone else out there has encountered this bug but here goes nothing. In the boss fight within the Presage activity, I just encountered a bug that killed my flawless run. After clearing the upper floor, I went to activate the switch in the "hot room". The switch was activated correctly which would normally turn off the heat just in time to spare your life. In this case, the floor did not stop damaging me and ended up killing me well beyond the normal deactivation time. I thought I might be going crazy but I took special care to double-check that I was at 100% HP before entering the room to flip the switch. I have no issues running Presage again at a later time but I thought I'd put this out there in case anyone else has come across this problem.