Continuity mistake: Before Nuclear Man sees Lacy's picture he flies up and produces a big cloud of smoke, which disappears a frame later from a different angle.
Sacha
Continuity mistake: Lacy flirts with Clark and places her left hand all along his shoulder. A frame later her hand is close to his neck.
Sacha Continuity mistake: At the hotel Jeremy walks to meet Mr. Warfield. In the first angle of him entering there's a bellboy walking in front, yet a frame later, from a close-up, the bellboy is now standing still a couple of meters behind.
Sacha Visible crew/equipment: When Superman cries "Don't do it, the people" a boom mic is reflected on the glass behind.
Sacha Continuity mistake: Nuclear Man kicks Superman and sends him flying hundreds of meters away from the Statue of Liberty towards the sea, but Superman's cape falls down straight from above the torch.
Sacha Continuity mistake: When Superman activates his laser vision to cut a mountain he moves his head from right to left, but from his POV the laser beam hasn't appeared yet, plus when it does its position doesn't match Superman's head.
Sacha Continuity mistake: Lois opens Clarks's door and stands in the shadows talking to him. The amount of light by the door swaps from gloomy to totally lit depending on the angle, with no order whatsoever.
Sacha Continuity mistake: Superman holds the tip of the mountain with his body straight, as if standing on air, yet a frame later his body is laying along as when he flies.
Sacha Continuity mistake: When Nuclear Man first shows up, a sculpture to his left appears and disappears between shots.
Sacha Continuity mistake: Amount of rock from the cut-out mountain standing out from crater differs between the first and second shot.
Sacha Revealing mistake: When the first cab is attacked by Nuclear Man, watch underneath and you'll notice that the wheels don't touch the ground, revealing it's a prop.
Sacha Continuity mistake: Lex greets Nuclear Man extending his hand parallel to the floor. A frame later the hand is tilted sideways, perpendicular to the floor.
Sacha Revealing mistake: When Nuclear Man steals the Statue of Liberty, there's a very obvious blur around the retouched image where the real statue has been painted over to simulate it's gone.
Sacha Continuity mistake: A US flag appears and disappears from Lacy's table when she flirts with Clark.
Sacha Continuity mistake: When Superman is locked inside a block of ice, the first shots shows it's semi-transparent, but a frame later it's opaque.
Sacha Revealing mistake: When the police cars drive backwards, before they crash and burst, the scene is a repetition of a previous one but reversed.
Sacha Continuity mistake: Nuclear Man crashes through Lacy's ceiling to abduct her, producing a perfect squared hole, with lamps on each side. When he exits, the hole is smaller and with an irregular shape, plus the lamps are further apart than before.
Sacha Continuity mistake: When the Statue of Liberty plummets, the building behind changes style, and also swaps from bronze to concrete.
Sacha Continuity mistake: When Luthor steals the strand of hair, Lenny stands inches away from him. A frame later he is in a different position 3 meters away.
Sacha Visible crew/equipment: During the city attack, after Nuclear attacks a bus, a boom mic is reflected on a cab's windshield. (01:10:25)
Sacha 
Answer: This is just one of many plot holes in the film. Whether she was at the edge of space or actually beyond the atmosphere, she shouldn't have had enough oxygen to remain conscious.
Jason Hoffman