I had a cat who would love to get petted, and just "eat it up" , rubbing her head against you, etc., and suddenly scratch you and run. (Not bite)
The vet said sometimes a cat will have a sensitive spot that itches so badly it is intolerable. The cat will then strike out, not knowing what else to do to stop that awful feeling and run away. I used caution and counted the pats I gave her, and warned everyone who wanted to pet her, because she really enjoyed the petting at first, and there was no warning. It didn't happen every time, but when I got scratched, I remembered it for a while!
The vet said sometimes a cat will have a sensitive spot that itches so badly it is intolerable. The cat will then strike out, not knowing what else to do to stop that awful feeling and run away. I used caution and counted the pats I gave her, and warned everyone who wanted to pet her, because she really enjoyed the petting at first, and there was no warning. It didn't happen every time, but when I got scratched, I remembered it for a while!