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.
The Other Slide Of Darkness - S3-E21
Plot hole: Quinn once again meets the alt-Quinn that he met in the pilot episode. Alt-Quinn tells our Quinn that he remembers solving the final part of the equation on his chalkboard. The problem is, there are many...possibly an infinite number of Quinn doubles in the multiverse. How could alt-Quinn have possibly known he was talking to our Quinn?
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.
Continuity mistake: In the scene where the Sliders are walking along pushing the dead car and are intercepted by the army, watch John Rhys-Davies' hand placement. As he confronts the troops, the scene goes from him placing his hands in his coat pockets to a back shot of him clasping them behind his back. As the conversation continues, it cuts to a front shot where his hands are, once again, in his coat pockets. Every time the camera shifts from front to back, his hand placement changes with it.
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.