I think there is a significant difference in the Hound pre-Blackwater vs post-Blackwater. He was fine as a simple soldier and killing machine serving his house and banner, started to struggle with being a sadistic tool of Joffrey serving the king’s random insane impulses, and then snapped at Blackwater and no longer served anyone but himself.
Tyrion never had any experience with the “enlightened” Hound, only the mindless soldier. I actually think that Tyrion’s jabs were an influence on the shift in the Hound’s allegiances, he didn’t receive the slightest bit of respect or fear from Tyrion, the sole person who might find kinship in the Hound’s existence as an abused disfigured tool. Instead he only received contempt.