Nothing alarming in your info, any chance you may have just startled him (or your cat did) and he was settling down when you put your hand in?

I'd keep an eye on him and maybe do extra water changes for good measure but if his behavior stopped it was most likely a reaction to stimuli in the environment and no anything physically wrong with him.

It might be a good idea to pick up your own liquid test kit (They last forever!) so that should anything odd happen again you have your testing right there and can see the values. The strips can be quite inaccurate.