I wouldn’t worry about tampering. The contract terms were pretty certain wherever he was going outside of CHA (max). It’s pretty easy for an agent to play the middle man in these types of negotiations.
I actually think the Al negotiations are much more egregious. They apparently already have worked out the number of years and salary at a non-max figure. I don’t really care (I keep seeing people claim that everyone was complaining with Al, but looking the other way with Kemba - I don’t really think that’s been the case).
Either way, if a player isn’t talking directly with the team, then it isn’t tampering. If they don’t want teams talking to agents either,, then they need to change the rules.