I have 3 cats. My lap is covered in scars and cuts because my cat likes to sleep on my lap until she gets spooked by some imaginary things and jumps off. They use their claws for jumping, so that alone left me those cuts lol. I also had 'dot' like bleeding from their claws. Upon further review, the claws went straight in, instead of slashing across. In my opinion, this does more damage than across. You have to deal with bleeding inside, with obvious signs of bruising.
Due to my own error, I also lost a snake to my cats. It happened so quickly, and my cat Gizmo who is the hunter in the house, is quicker. The poor snake didn't survive after 24 hours.
Cats don't just use their claws when hunting. They stab, pull, bite, and do that some more until they are sure the prey it's dead. So your snake may also had been bitten. Cat bites are a serious concern for people too.
I never leave my snakes out for too long during cleaning and they are always placed in a spare lockable terrarium. You never know when you have to stop what you are doing, got distracted for a few hours and come back to no snake.
In the end, I understand the guilt you feel. Do what you can, let's see if the vet can confirm the injuries. Whatever happens, learn from it, and move on.