Pod aliens remain slow if shot as soon as they finish hatching

[ZeuxWarrior]

Normally, pod aliens speed up after hatching once you've shot them once. Somehow, I got a hatching pod alien to remain slow, no matter how many times I shot it afterward, by shooting it the moment it finished hatching. The weapon I used was the auto-charge pistol, and I shot the egg to open it instead of waiting for it to hatch (don't know if it makes a difference, though).

I only bring this up, because I don't remember this being a thing in the vanilla AoG.