Continuity mistake: When the Kromagg leader goes to eat an eyeball, he stabs his fork into a green eye. In the next shot when he lifts it up, the eye is now blue.
Continuity mistake: When the Sliders see their first bunch of Welcomers get zapped, there is a short blonde woman in that group. We know later in the episode that these people are being burned to ashes; so she is now dead. In the final scene of the episode, that woman is in the audience.
Continuity mistake: When the Kromagg sub-commander captures Quinn in the kitchen area, Quinn is leaning back, away from the knife. The sub-commander is a good 8-12 inches shorter than Quinn. The camera angle changes, and now the sub-commander is about 6 inches taller than Quinn.
Character mistake: Maggie and Rembrandt go into Alt-Colin's room thinking it's their Colin. But then begin to question when he had time to buy a suitcase, get his stuff monogrammed, and where he would get the money for it. When they find Alt-Colin, he has expensive jewelry on and is acting weird, saying "homie" and hitting on Maggie. And yet they still act like this is their Colin and don't think about it being his double, despite the fact that they constantly talk about and met their doubles.
Data World - S4-E17
Continuity mistake: When Mr. Chandler is on the roof with Quinn and says they should talk in his office, he's standing on Quinn's right side. In the next shot, Mr. Chandler is on Quinn's left side.
Continuity mistake: Near the end of the episode, when Maggie goes into the Suspended Animation chamber, she shoots the Pressure Control box & destroys it. The Temperature Control box is not hit. Moments later, the Temperature Control box is the one that's destroyed.
Revelations - S4-E22
Revealing mistake: When the group is fleeing from the cops, there's a shot of the road as they're turning. The camera used has a crack, or piece of debris, on it at the top to the left. The black line doesn't move as the camera pans across the road.
Chosen answer: Remember at first Quinn's timer is working perfectly (it's only because they slide off the ice age world early that it begins to malfunction) & given Quinn's intellect he would have devised a way that he could open a wormhole near him so he wouldn't be trapped on that world for 29 years.