Small corn snakes don't have a strong grip, but larger corn snakes will be much stronger- & keep in mind that a snake that is not comfortable with you may intentionally let go at any time with an intent to flee, so you you always need to be a "spotter" (like in gymnastics- the side person that makes sure the athlete doesn't fall, & especially not in a way they get hurt).
For whatever reasons, some snakes just rely on us more to hold them, while others grip ridiculously tight (like my spotted python!)- anyway, I'm glad he landed well. He expressed his stress rather predictably afterwards...
If anything these experiences are just making me glad I went with a corn after a BP. If going from a large, slow BP to a small, slightly flighty corn is giving me whiplash, I can only imagine it would've been twice as bad if I went straight to a VBB.