Something to remember, if you look at the core best lineup (Bradley-Green-LeBron-AD-Dwight), crazy thing to note is that NONE of them were playing together before this season and NONE of them had played for Vogel either. So everyone's getting used to the system and used to each other. You get in those pressure situations and you still have to think about exactly what the play is and getting used to what you're looking for....the kind of things that become second nature once you've been playing in a system for 1-2 years. Those sort of mistakes were happen, even though the chemistry feels great you gotta have time to work out the bugs.
And I don't know if it's actually a factor, but I mentioned a few weeks ago that managing Danny's minutes should be a thing. He's starting to get to the point where he's noticeably aged and the last two years he crashed in the playoffs. They have a ton of guards, once they feel the chemistry in the core lineup is good they should really start limiting him to under 25 minutes/game on a nightly basis and maybe even think about coming up with an excuse to sit him for 2-4 weeks in January or February so he can be complete fresh for the postseason.
Load management activated right before the Hawks.
Seriously, if it's tendonitis or anything like that then he needs to sit for a while. I had tendonitis in the elbow a few times from weightlifting and the doctors said the ONLY thing you can do to heal it is total rest.