Didn't they boot him for a ToS violation?

> Any lawyer can file a complaint in small claims .

No, in many states _no_ lawyer can file a complaint (except his own) in small claims court.

They booted him for TOs violation, that was their action. A judge can decide whether that action was a breach of the contract, or if the contract itself is lawful.

We live in a common law country. It means that the judgement defines the law, not contracts (and not even statute, strictly)