Character mistake: One of the top most taboo things for a super hero to do is reveal any aspect of another hero's identity to someone, especially a villain. But when Flash is trapped by the gray adhesive and the other Justice League members are about to take the villains away to disarm the bombs, Flash tells Green Lantern "Hal, go", calling Green Lantern by his first name right in front of Mirror Master. (00:08:05)
Continuity mistake: When Barry is looking at the gun case in the Batcave, a cork board is visible in the background covered in raggedy playing cards. The one to the left of the center Joker card has blood on it, a lot of it around the bottom right corner of it. Later when Batman looks at the cards, the blood on that card is significantly less. There is also a card to the right of the Joker card that is torn with no blood on it. But in the close up when Batman is looking at it, that card now has a large blood spot in the center. The card symbols on the cards are also closer together, the cards above the Joker are significantly less damaged, and change from suit of hearts to a different suit. The entire board seems different. A few shots later, the cards above the Joker card are back to hearts again. (00:20:45 - 00:25:30)
Deathstroke: That's a lot of death... Even for me.
Trivia: After the ending credits, there is an additional scene showing an alien invasion appear from a temporal rift. This is likely an homage to the upcoming movie, Justice League: War, which is the story of the Justice League first forming in order to combat an alien invasion. (01:20:50)
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