I hate to support Cuban on this, but he does have a point. If Nellie wants the contract enforced so that he can get paid the money that is owed to him under it, that same contract does in fact include a clause prohibiting him to compete against the Mavericks. Statute of limitations on the breach is 4 years, so Cuban is still within his rights to sue under the contract (if it is indeed held valid). If the contract is not valid, then the no compete clause dies, but so does the obligation to pay Nellie (at least after the breach of the material term, in this case the no compete clause). Not knowing much about the situation other than what's been reported in the media, I'd guess that Cubes has to pay consulting fees up until the time that Nellie joined GS, but not after. However, I don't think Cuban's all-or-nothing assessment is correct. Nellie will get what he was owed under the contract until he breached one of the material terms by coaching another NBA team. I guess another way to look at it is that if the contract was breached when Cuban refused to pay Nellie before Nellie in fact later breached, he will get the value of his services up until that point, and any other damages he incurred by relying on the contract. It's unlikely he will get the full ~$6 mil since he did in fact breach and the contract was for Nellie's services as consultant which he did not complete.