Continuity mistake: Carter and Cadet Haley enter the Stargate and we see them through the "puddle." When they come out on The Other Side, their positions are reversed.
Beware the Third Wish - S1-E31
Continuity mistake: The Wicked Wisher throws giant exploding coins onto the field TJ is on, as TJ runs towards the WW. The giant coins remain on the field after they explode, yet when TJ reaches the top of the field, there is no sign of the coins, or their remains.
Continuity mistake: As the prisoner transport ship is unloading in a shot from behind Stanley at his station, several of the prisoner frame things holding them are being moved along the line. And Xev can be seen back a ways in the line, identifiable by her fat body in the white wedding dress. There are at least six other prisoners on the line in front of her. But then as the line stops when reaching the Holo Court, Xev is suddenly second in line with only one person before her. The woman in the blue body suit is still behind her though so she also moved up to be third in line. (00:22:20 - 00:23:10)