No biggie - I beat it again the next day without it. Felt a little more legit, too! As you had it implemented, it was basically something you always wanted to take, since it only really helped the player (although I did spawn on top of an explosive and die instantly once).
Edit: You probably already thought of this, but why not just make it so that explosives can only damage the player when they are below 4 HP? I think there are some really interested trade-offs in that kind of a mutation, and it fits the theme of being 'Reversed' in my opinion.