In the US, generally it is binding. Communications and agreements between parties are binding particularly if TK received something in return for said promises

In the US, generally it is binding. Communications and agreements between parties are binding particularly if TK received something in return for said promises. Even verbal agreements are binding in the US especially when dealing with parties such as these. If TK hopes to have any credibility moving forward, with the Board or in the courts, it would be in his best interest to keep commitments or he will be stuck in the "did you lie then or is this version a lie" mess. If he wants to argue that he made the agreement under duress then he can argue that in court and the court may find the the agreement is not enforceable but duress can be a steep hill to climb without physical, or threat of physical, harm.