Continuity mistake: Aquaman coughs up blood after he is stabbed by Wonder Woman. Some blood goes on his chin. Throughout the rest of this scene, the blood on his chin keeps going from the right side to the left side of his chin. (01:10:25)
Continuity mistake: After Batman shoots Reverse Flash through the head, Flash rushes over to Batman and catches him before he falls over from his wounds. As Flash is lying him down slowly, there is no blood on Batman's face. It then cuts to a close up as Batman reaches up to pull off his mask and there is suddenly blood on his lips and chin. (01:12:20)
Continuity mistake: When Barry lays flowers at his mother's grave, the base of her tombstone changes style between the close up and when he stands up and runs to his wife. (01:15:25)
Continuity mistake: Barry places a bouquet of flowers on his mother's grave at the end of the movie. The bouquet is upwards to start with, but lying on the ground when the shot cuts. (01:15:25)
Continuity mistake: After Flash fixes the timeline, he is back in Bruce's Batcave and gives Bruce a letter from his father. Bruce is working at a station and his utility belt is there as he is working on it. When the camera pulls back before Flash runs off, his utility belt vanishes. (01:17:00)
Chosen answer: Thawne spent his whole life wanting to discover the speed force. When he did, he became The Flash of his time. But Thawne couldn't live up to Barry's legacy. It drove him mad. And drove to eliminate Barry.
MasterOfAll