Regardless of events leading up to that injury, Boston made right call getting rid of him instead of giving him some max contract after the injury.
Instead of being able to walk away from the Kyrie mistake, they'd have one of the most toxic contacts in the NBA. It's a business, loyalty matters but there is such thing as loyalty to a fault.
At the end of the day, IT was never the same player, he was so messed up Cleveland almost reconsidered the trade. He never would've been worth the contract he wanted, where is he even playing now?