Continuity mistake: Just after Wonder Woman and Aquaman argue a brief moment about her killing his wife, they continue their fight. Between the close up and the far shot, the rubble by the wall they are next to changes significantly in shape and amount. (01:00:20)
Continuity mistake: After dodging a low attack, Wonder Woman jumps into the air and slashes down at Aquaman with her sword. Aquaman raises his trident and blocks the attack, but is only holding the trident with one hand. It cuts to a close up and instantly Aquaman is two handing the trident. (01:00:25)
Continuity mistake: While fighting in the building, Wonder Woman gets up from some rubble and throws Aquaman through a wall leaving a hole. She then chases after him and they talk for a moment before suddenly Flash comes in and starts pounding on Aquaman. Cyborg then blasts Wonder Woman backwards. She flies at the very same wall, but now there's no hole and she makes a new one going through it. You can tell that it is the same wall as when she and Aquaman went through it the first time, her back was to the wall. She never changed positions or location at all until Cyborg comes in, and he blasts her straight backwards. (01:00:35)
Continuity mistake: After crushing the skull of an Amazon, Black Manta who shoots concentrated heat vision turns his attention to Batman. There is a purple car beside him. A couple shots later before he blasts at Batman, the car has turned black, and moved a lot further away from him. (01:01:35)
Continuity mistake: Batman is blasted against a green car by the guy with heat vision. He runs to the next vehicle as the heat vision guy shoots a ray at the green car, and the next shot shows the car is now purple. (01:01:40)
Continuity mistake: While fighting Black Manta, Batman stands next to an orange car as he blasts away with his pistols. Between shots, the front seats of this car change from separate seats to a bench seat. (01:01:45)
Continuity mistake: When Batman starts shooting at the heat vision guy, an orange car is behind him. The shot cuts and he is suddenly standing with the car on his left. (01:01:45)
Continuity mistake: While Batman is fighting Black Manta, he dives over as the bad guy blows a car into the air. The car is a light blue color and falls over on Batman. The next shot as Black Manta is walking towards it, the car has turned to a light orange color. Moments later when Batman crawls out of that car, it is back to being light blue. The car it lies on also changes from purple to orange. (01:02:00)
Continuity mistake: After the car falls on Batman, Grifter begins shooting at Black Manta. He is standing on top of a yellow car. When Black Manta begins shooting heat vision at him, the car turns green. (01:02:05)
Continuity mistake: Reverse Flash stabs Flash in the leg with a broken rebar. In the side shot, Flash throws his head back. It cuts to a close up of Flash, and he throws his head back again and screams. It cuts several times between a close up and a side shot at this point. In the side shots, Flash has his lips open, but gritting his teeth hard. In the close ups, Flash's mouth is wide open. (01:04:40)
Continuity mistake: After Reverse Flash stabs Flash in the leg with a rebar, and Flash retaliates by smashing a rock in Reverse Flash's face, watch Flash's hand. There is a rip in his costume on his right hand over his index finger knuckle when it cuts to a close up of him reaching for the rebar. But the previous shot shows no rip on his hand. (01:04:45)
Continuity mistake: After Reverse Flash stabs Flash in the leg with the broken rebar, Flash picks up a rock and slams Reverse Flash in the face with it. In the wide shot of this, the rebar is a solid gray bar. It then cuts to a closer shot as Flash grabs it, and suddenly there are screw like lines swirling around it. (01:04:45)
Continuity mistake: When Reverse Flash stabs Flash in the leg with a piece of rebar, Flash is on a small pile of rubble. He takes the bar out and drops it on the rubble. But then it cuts to a different angle as Reverse Flash continues to assault Flash, and suddenly Flash is in a different location, with no piles of rubble in his immediate area. (01:04:50)
Continuity mistake: Reverse Flash smacks Flash over to the edge of a building. The building is heavily damaged from the war and crumbling. The edge is broken off and jagged, but averages out to a straight line. A few moments later, when Reverse Flash puts his foot on Flash, the broken edge of the building has become much more jagged and uneven. (01:05:40)
Continuity mistake: Reverse Flash knocks Flash back and he is next to the edge of a building, his arm hanging over the side. Flash sees Grifter get killed and tries to get up, but Reverse Flash presses him back down with his foot. Flash is still right next to the edge of the destroyed building. The Reverse Flash zooms around behind Flash, and suddenly there is at least a good 2 feet between Flash and the edge. Moments later, Reverse Flash kicks Flash and he goes over to the edge again. (01:05:40)
Continuity mistake: Wonder Woman tries to stab Captain Thunder with her dagger and just breaks it on his chest. She then has to drop the broken blade to catch his fist as he tries to punch her. She then uses both her hands to use her Lasso of Truth to make him say shazam and break his form. The lightning bolt hits her and she flies off him as he reverts back to 6 children. As she stands up, the broken dagger is suddenly in her hand again. (01:08:35)
Continuity mistake: Wonder Woman stands on top of Captain Thunder and uses her Lasso of Truth to force him to say Shazam, breaking his transformation and turning him back into the 6 kids. This causes lighting to come down and strikes Wonder Woman, sending her flying and sliding across the ground. When she comes to a stop, her hair is draped over her head. The next shot, she begins lifting her head and her hair is suddenly behind her head down her back again. (01:08:55)
Continuity mistake: Just before Aquaman can stab Cyborg's heart, Superman cuts off his arm with laser vision and it falls to the ground beside him with the trident. A little later when Cyborg dies and Superman is kneeling beside him, it cuts to a wide angle. Aquaman's arm and trident are nowhere to be seen. It was not blown away by Superman's breath either. (01:09:50)
Continuity mistake: After Aquaman finds Orm dead and sees the carnage of the battle, Wonder Woman comes up behind him and stabs his back with her sword. He falls to his knees and she walks around in front of him, and as she does you can see there is no blood on her sword. But then she holds the sword to his neck in a close up and suddenly the sword is covered in Aquaman's blood. (01:10:15)
Continuity mistake: After Wonder Woman stabs Aquaman, she points the sword to Aquaman's neck. The direction of the sword changes between shots from vertical to horizontal. (01:10:20)
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.