Mutation doesn't kill -nearly- as much as Chaos Seed. Chaos Seed does, on average, 3.2 damage. We have 6 of 'em. Eggs have 1 HP. Do the math if you weren't there for a previous Egg tourney.
Sounds like misplay. 3.2 < 5. l2p
Also damage being averaged is inappropriate vs 1hp. What if one of cseed's effects were 100 damage? 8/12 cseed effects will kill an egg. Not counting lobo or infect, that's only 50%. Only infect, lightning, & well quanta'd bolts will kill abom, which could be said to be ~25% (have to take into account kill chance tho, but then there's also the matter of improved not dying to lightning)