You manually brought the drone down to two feet above the ground and released the left stick.
The drone had been directly above the homepoint, but as you descended it drone drifted to about 35 ft from the homepoint.
You left it hovering and pulled left stick down three times for about a second, then left it hovering for 20 seconds.
At 19:05.0 there was a warning of Low Battery, drone would return to home and the Flight Mode changed to RTH.
Shortly after this, you pulled the left stick down again and then the drone started to rotate to point towards the homepoint.
As it started to fly towards the homepoint, you fought against RTH to lower and turn the drone.
The drone returned to the homepoint and had a slow speed collision at 19:21.5.
The drone stopped a few feet off the ground and would not land. I was landing on a paved parking lot but the controller said something like "unsuitable landing area".
The battery was running down and the drone would not respond to inputs to move in any direction. I pushed what I thought was the land button and the drone lifted and began flying toward a nearby building. I couldn't get it to stop or turn and it hit the side of the building and crashed.
You got the impression that the drone wouldn't respond to your joystick inputs because the drone was trying to RTH.
You didn't cancel the RTH and tried to fight against it.
At the time of the collision, GPS indicates the drone was two feet from the recorded homepoint.
It's not safe having the homepoint close to obstacles
But I am concerned about the way the drone behaved when it wouldn't land,
I can't see an unsuitable landing spot message in the data, but if there was one, the correct action would be to move to a different spot and try landing there but you kept the drone at the same spot.
why it turned and flew toward the building
It went to Low Battery RTH and was following the RTH programming.