1. Space. Paul George gave him tons of space right until he shot the ball. He wasn’t bodying him up, he let him be comfortable. George didn’t touch him the whole time he guarded him. Think about how many times Dame has practiced a step back three (at any spot, not just there) with nobody touching him. He’s made his body do that move probably thousands of times. Muscle memory kicked in and he hit the shot. If he’s closer to the basket, George is closer to him, probably bumping him. If he was closer, George would have been tighter on him, bodying him up. It would have been much more difficult to hit that shot, especially considering how much longer and heavier George is than Lillard. George is one of the best defensive players in the NBA. A closer shot doesn’t guarantee a better shot.
2. Help defense. If Lillard had driven, he would have had a contested layup with George on him and a big coming in to help. I would rather have an open stepback three than a contested layup, especially when the refs are more likely to swallow their whistle.