I agree that Kyrie is occasionally prone to hero ball, but I don't think either of those final three-pointers qualify.
For the first one, he got the ball back with time running down on the shot clock and had to make something out of nothing with Wall draped all over him. Got off the best shot he could in that circumstance.
The second one (the deep three) is more of a stretch, but I don't think that's that low a percentage shot for him. It's deep, but it's a clear look with Wall several feet away with his hands down. If you consider that a 33% shot for Kyrie, which is a 50% eFG shot, that's not bad in end-of-game, tense situations. When you consider how short-handed the team was yesterday and the fact that Kyrie had it going, then I can live with it.
Earlier in the year when the Celtics were struggling offensively in the beginning or middle of games, I saw him try and shoot the team out of their funk single-handedly. That, I think, was a problem, because it wasn't sustainable. But that's different from what we witnessed in OT last night.