Continuity mistake: When Barry-1 and 2 fight outside their home, the position of their hands has no continuity at all between shots.
Continuity mistake: When Old Barry meets Young Barry outside their home, the way the underwear folds on Old Barry's face differs between shots.
Continuity mistake: When Young Barry slouches on the chair to eat peanut butter, the way the left side of his robe falls on the chair differs between shots.
Continuity mistake: After Young Barry vanishes, Old Barry holds the robe from the upper part. When Young shows up, Old's hand is nowhere to be seen; the grip has changed.
Continuity mistake: When Young Barry vanishes in the kitchen, the way his empty robe folds changes between shots. Also, the spoon falls on the robe but suddenly appears on the floor a shot later.
Continuity mistake: Barry spits the broccoli and some gets stuck on his lower lip. A shot later it has vanished.
Continuity mistake: When Young Barry enters Old Barry's home, he puts on a robe with a teddy-bear hood. The way the left side of the hood is folded changes between shots.
Continuity mistake: Barry is ordering at the café, and a man with a beard and a man bun walks behind him. An instant cut later, he's already on the other end of the counter. Too fast. Also, the people standing or sitting behind the counter are not continuous between shots.
Continuity mistake: When Young Flash agonises, he is handed a teddy bear whose face is visible. An instant cut later, the teddy bear has turned around. Then, yet a shot later, it's turned again and you can now see his face.
Continuity mistake: When Young Flash is dying, Old holds him in his arms, both bodies next to each other. After Dark Flash vanishes, from the opposite shot of Old Flash he is not holding anyone, just mimicking as if he were. You can see through the gap between his arm and body. A shot later Young Flash reappears.
Continuity mistake: During the Gotham chase, a group of kids get off the school bus, cross the street, and stand in the middle of the road. When Batman launches the puncture spikes, they get off the bus again.
Continuity mistake: When Kara flies upwards holding Barry, she turns her head towards him. From a side angle, her hair is motionless despite the wind and speed. The angle changes to a front shot, and now her hair flutters wildly. (01:36:13)
Continuity mistake: Flash arrives in the past and lands next to the kerb, where he leans on to help him stand up. A shot later, he is several metres away, near the middle of the road.
Continuity mistake: When Flash sees his mum shopping, she is holding a cereal box. From the angle shot from behind, the box is gone.
Continuity mistake: Young Barry is lying half a metre away from the wall. A shot later he is 3 metres away. (00:45:10)
Continuity mistake: Old Barry replies to his dad that "school is good, school is great," and gestures raising his right hand. From a side shot, it's lowered. Then back to a front shot, and he is lowering his hand.
Continuity mistake: When the group enters the Siberian elevator, Kara's arm is bent. A shot later, it hangs down her side.
Continuity mistake: When the Barrys, Kara, and Bruce exit the Siberian lab, they encounter an employee. At first, the top of his hat is wrinkled. A shot later, it's stretched upwards. This swaps back and forth.
Continuity mistake: In Batman's lair, after Barry has been electrocuted, the blood on his nose and mouth suddenly vanishes.
Continuity mistake: Old Barry collapses next to Young Barry, and lies next to his waist. A shot later he lies next to his head.
