I've never attempted an assist; wouldn't trust myself, but your explanation made sense to me. I knew there was a reason I got up this morning; that must've been it.Ant's air cells were too big too early. Had to slow the growth on them so the chicks would have enough room to move into hatching positions. Too little humidity when the chick pips/zips will make the membrane tough. If you've ever pulled an egg to assist, you'll know that the membrane dries and starts turning brown very quickly. It's drying out and turns rubbery, which can be nearly impossible for a chick to tear though...