just to be clear what we are saying, i'm pretty sure the squirel in the pictures is just a regular squirel, like a grey squirel that can not glide away.
I flying squirel, sometimes southern people call them sugar gliders, have noticable skin flap between front legs and back legs and can glide away considerably. Much smaller animal, and look "cute" with the big black nocturnal eyes. A true flying squirel would not fall straight down like that and you would have seen the skin stretched out.
grey squirels that can't glide, can slow themselves down a good bit by stretching out though. I've seen a few drop fairly slow. But are very tough, can take a big fall.