Apparently a lot of people one hit the nemesis bot with a big gun- dont know why it happens but feels great to crit for 3500
I don't know the specific crit table for that critter, but I guess it's a "death" effect that makes that much damage. When you score a death (which is basically a one shot) you deal the exact amount of HP the critter/player has left, puting him on 0. I made some tests and it seems it cannot trigger if the damage from death is lower than regular crit. So, no matter how many HP/damage output you have, you will kill anything with any weapon, if you have better criticals it helps ofc. Go hunt centaurs with a BB gun, you'll see, it's funny.