Who said he found the cat as a stray? Why it was the same person who claimed he owned it. What a coincidence. I had a dog stolen - lifted right out of my back yard. When it was recovered (because fortunately someone saw who took it) the thief claimed he didn’t know it belonged to anyone. Ie a stray.
Funny. That did not seem to be the contention of the owner. Because they seem to have accepted the fact that their pet strayed.
I think you might be engaging in a bit of projection.