Continuity mistake: In the Batcave, Batman gets off a good punch to the side of Barry's head and knocks him over to a medical bed. There are two wine bottles on the floor next to the bed. A couple shots later when Batman is walking up to him, the beer bottles have vanished. (00:20:55)
Continuity mistake: When Steve Trevor is running from the Amazons in the destroyed Big Ben, he leaps from a ledge and crashes through several boards on the way down as he shoots back up at the Amazons. When he hits, he rolls to his feet with broken boards all around him and several arrows hit the ground that the Amazons fired. When he takes off running and shoots back at them again, you can see the Amazons jump down to that very same spot before Wonder Woman's lasso catches Steve. The broken boards and the arrows have vanished. (00:21:55)
Continuity mistake: When Wonder Woman is interrogating Steve Trevor, other Amazons are standing around her. Between shots when another Amazon appears, some of the Amazons' sword sheaths and other items on them change coloration. The one on the far right first has a gray sheath with a yellow tip, which then changes to solid yellow. Her collar also changes from yellow to black. And the one closest to Wonder Woman has a sheath that goes from a gray with yellow tip to a solid gray. The Amazon closest to the camera also has a quiver for her arrows. It changes from yellow to brown. And the one between the one with the yellow quiver and the one on the far right is wearing a white skirt with a black band around the waist. The band turns yellow. (00:22:40)
Continuity mistake: After Wonder Woman snares Steve Trevor with the lasso and begins interrogating him, the other Amazons that were chasing him walk up in front of Wonder Woman. There are 5 Amazons there, including Wonder Woman. A few shots later when she's holding Steve up, a 6th Amazon girl suddenly appears with the other 4 that were in front of Wonder Woman, standing almost behind Wonder Woman but to the side. (00:22:40)
Continuity mistake: As Lex Luthor is discussing the shockwave epicenter with Deathstroke, he places his finger on the computer screen about an inch away from the Epicenter blip down to the left just as the orange moving blip begins going across the screen again. The orange blip makes it almost to his finger before it cuts to a close up of the screen. Now suddenly Lex's finger is much further away from the epicenter blip and sliding to the right, with the orange blip in front of his finger. (00:26:40)
Factual error: After Lex Luthor and Deathstroke step out onto the deck of Deathstroke's ship, Ravager and begin talking, Aquaman's sub surfaces and smacks into the Ravager and it shakes violently and lurches. Yet the crew, Lex, and Deathstroke stand perfectly still just moving their arms around a bit. An impact on a ship like that would send all people standing up falling everywhere with no balance. (00:27:10)
Continuity mistake: Once Aquaman's forces begin attacking the Ravager, people begin dying left and right from both sides all over the ship. These bodies keep disappearing as the fight goes on. (00:27:30)
Continuity mistake: On the deck of the Ravager, there is a large flak cannon that one of Deathstroke's men turns on Aquaman's forces. One of Aquaman's men destroys this flak cannon into a large ball of fire. Then a guy stands back up and turns into Clayface and begins absorbing some of the enemies. Orm uses his staff to obliterate this guy and behind him is shown where the cannon was. There is no fire, debris, or any sign of the destroyed flak cannon. (00:28:35)
Continuity mistake: After fighting for a brief few seconds, Black Manta kills Deathstroke by burning a hole through his chest with his heat vision. Deathstroke falls right next to Lex Luthor as his chest sizzles and his swords fall around him to. A couple shots later as Black Manta is picking Lex up, Deathstroke's body and swords have vanished. (00:29:35)
Continuity mistake: When Wonder Woman is sharpening her sword, the direction of the sharpener changes between shots. (00:33:45)
Other mistake: In the flashback of Bruce Wayne getting killed, his mother is cradling his body and weeping. She has his blood all over her hand from touching his wound. She rakes her fingers across his shoulder and down his chest with her bloody fingers, leaving no trail of blood, but when she places that same bloody hand on her face it leaves blood all over her face and mouth. (00:35:05)
Continuity mistake: After Barry wakes up in bandages with third degree burns all over him, there is a spot of blood on his chest below his left shoulder. A good amount of the blood stain overlaps a line dividing two strands of the bandage. Moments later when he sits up, the blood is barely above that line at all. Later when Barry is sitting in the chair again, that same stain has completely changed shape. Other patches of blood on him also change. (00:36:20 - 00:38:00)
Audio problem: The scene after The Flash regains his powers and saves Batman, we see Lois Lane running through a street. Her speech doesn't match what she says. (00:39:00)
Revealing mistake: When Lois Lane jumps into a trench whilst she is being chased, there is a vertical lined zip on her jacket. She turns her head partway and the vertical shaped zip on her jacket disappears for a frame or two. (00:39:10)
Continuity mistake: Lois hides under a purple car. It becomes red after a beast walks over the bridge. (00:39:15 - 00:39:45)
Continuity mistake: The bridge Lois hides under has several impact holes on the side of it from the war. These holes change in number and position in different shots of the bridge. (00:39:35)
Continuity mistake: While hiding from the Amazons under the bridge, Lois Lane hides by a purple car. There is an upturned blue car on the opposite side of the bridge there as well. This car disappears when the Amazons jump down to her and reappears again in the scene, also changing position a few times. (00:39:40)
Plot hole: After Reverse Flash saves Lois Lane and kills all the Amazons that were attacking her, he disappears, just before a group of resistance fighters shows up. They know that they didn't take out any of the Amazons, it's obvious that Lois didn't kill them, yet the resistance members show no concern as to who was responsible. The war involves three separate groups, the resistance, the Amazons and the Atlanteans, each of whom is equally hostile to the other two. As such, the resistance cannot assume that whoever killed the Amazons must be an ally and let their guard down, as it could easily have been an Atlantean force, who would make no distinction between the Amazons and the resistance and would attack them on sight. An experienced resistance team would not be so casual about the situation. (00:40:50)
Continuity mistake: When Flash takes off running in the desert trying to test if he can break the sound barrier, the lightning bolt on his chest is much wider than seen just a couple of shots later. (00:42:55)
Continuity mistake: After he gets his powers back, Flash takes off to try and time jump with speed. He fails and trips, sliding to a grinding stop out in the open desert. The shot from the side of him on the ground shows him lying on rolling "sand waves" and looks rather smooth with no vegetation around him except some cacti in the distance. The shot then cuts to an over head view as he sits up and starts to weep in desperation. Suddenly the rolling sand is now a dried cracked dirt and there are bushes and more cacti around him. (00:43:10)
Answer: Flash couldn't travel through time later in the movie not because Zoom was alive but because Zoom was also tapping into the Speed Force, preventing Flash from gathering enough of the Speed Force to break the Time Barrier. When Flash originally went back in time it's likely because Zoom was in custody, therefore not tapping into the Speed Force at that time.