I am pretty sure most of us have had that happen at some time when incubating, don't beat yourself up for it, my broody hens do that sometimes too or accidentally squash a newly hatched one under themI feel really awful, clumsy me dropped an egg in the incubator onto the rolls and cracked another one in doing so. The dropped one was a yolker, but the other one was developed! day 18! I killed a chick!
I was thinking about glueing it, but it wasn't a clean crack, so I had to throw it away. Sob, sob, even unhatched, they are my babies. So now I have 8 left in that incubator and I am now super glad I kept adding eggs in the other (safer) incubator. It's day 19 so those 8 are in lockdown now and I'm keeping my clumsy hands off them!