S.T.
I hope he gets a better job!
Yes, in the state of TX a verbal agreement is a contract BUT you have to have witnesses and if there's no proof that the judge may not side with the plantiff. He'd probably say "Why did you stay there 6 months?"
My brother in law worked for Walmart for years and had a lot of similar problems to that. He kept telling them he was leaving and then they'd offer an incentive to stay (which he never got.) Then one day he came to work and he wasn't on the schedule. He asked why and they said "Well, you keep saying you are leaving so we replaced you."
S.