I have a theory on Dak. Several times this year he's been bad most of the game but then somewhere in the late 3rd or 4th quarter he suddenly finds it and starts throwing darts.
I think he's too risk averse. We've seen the replays (and sometimes even live) of when he has guys open but he comes off of them to a checkdown, or even holds it too long for a sack. I wonder if he isn't being too careful. It's good that he's not reckless with his throws, but you also can't be afraid to fire it in there when necessary, either.
Later in the game when time is running out and we're behind, it's like he realizes there are limited possessions left, so he just goes with his first instinct and lets it go without thinking so much. You can see that not only are his throws physically better, but he seems more decisive and quicker in his decision to let the ball go. I think this is also why the hurry up works for him -- less time to think, more just reacting and cutting it loose.
Related, I wonder if his confidence isn't as great as we think. Maybe he's reticent to make those throws sometimes because he doesn't quite trust himself? But then later when there's basically no choice he has to go for it.