When Cyborg tries to access the Motherbox to close the Boom Tubes, it blows up in his hand. Yet in the very next scene it is back in his hand completely intact.
(at around 1h 12 mins) When Green Lantern flies off to catch the falling humans that are coming through Cyborg's Boom Tubes, in one shot Shazam is shown where Superman should be.
Green Lantern's right arm is broken and he encases his arm with a cast using the power of his ring. While doing so, his ring changes place from his right hand to his left hand. In the next scene when he tries to lead the other heroes, his ring disappears when he clears his throat and then reappears again after a while.
Wonder Woman's ice cream cone disappears between shots when the Parademons attack DC.
When Batman is holding DeSaad by the throat, the ligature on the left side between his upper and lower lips is missing.
When the President speaks at the end, the flags hanging on their side have the stars on the right. This never happens. When put on their side like that the flag is flipped as the stars are always on the left.
Batman unmasks himself in front of Hal Jordan, why does he do this??? This is not only extremely stupid but could reveal his identity to active security Camaras, other people, and any satellite in the sky. He is also Bruce Wayne, this could expose him, his company and put his allies and family in great danger. He has more to lose then anybody. No superhero would willingly expose there identity like this, it's just not done.
When Shazam says his own name to introduce himself to the other heroes, the lightning that transforms him from Billy Batson to Shazam, and vice versa, does not strike. However in the New 52 continuity (upon which this film is based), the word "SHAZAM" only works when he intends for it to. Otherwise he can say it without effect. This was necessary when they changed the character's name from Captain Marvel.
When Diana is coming out of the white house, she appears to go through the front gate. This is not a superpower of Wonder women. Clearly the animators
made a mistake, it's there but you have to look close, it goes by quick.
How is The Flash able to take out one of Darkseids eyes with a crowbar??? Everyone has either magical abilities or superpowers, and they don't seem to affect Darkseid much. This makes no sense, and is a definite mistake.
Why doesn't Hal Jordans ring not have healing abilities??? This is one of the most powerful weapons in the DC universe, it should easily heal it's ring bearer and maybe even other people. Yet it doesn't. This is a problem in a lot of the movies that feature the Green Lanterns, but it is a mistake here as this could have healed Hal and it could have been far more useful in the final.
We never see how Batman frees Superman from the Parademon infection. One moment he's trying to kill Batman, the next they are both coming out of the Boom Tube and they are completely fine. Not to mention they are now wearing some kind of armor chest plates that are never explained.
Right before the Parademons attack, Steve pulls Wonder Woman away from the ice cream stand saying that the President is waiting for them. Yet in Wonder Woman's next scene after the Parademons attack she has to fly up to Air Force One to rescue the President and the First Lady. How could the President be waiting for them if he was on a plane in flight?
Cyborg has to make a direct interface connection with the motherbox in order to close the Boom Tubes. Yet at the end he doesn't need it to reopen them and bring all the normal people back to Earth?
Why does Darkseid on of the most powerful characters in the DC universe leave his eyes open as weak spot??? Darkseid is intelligent, and very powerful. If his eyes were his weakness, shouldn't he have been wearing some king of
eye protection over them. This makes no sense.
During the final battle after when Darkseid's eyes were taken out, when Shazam uses his lighting on him,he was shown to have his left eye intact despite being gouged out.