It would be very easy to set up a situation for it to be just Quinn leading a new batch of sliders if Jerry is the only one to commit.
A couple of grad students are experimenting with wormholes, not 100% sure what they've stumbled on to. They've been sending "probes", basically just radio controlled vehicles with cameras and microphones attached, then retrieving them a few minutes later. So far everything that's been recorded has been very ordinary. A beach, a forest, a park, a basement, etc. They believe these are images of alternate universes but it's all so mundane it doesn't prove anything. Then, while trying to bring back one probe they get an anomalous reading from the tunnel. They assume an animal must have gotten into the wormhole with the probe. Not knowing what effect sliding would have on a living creature or whether they might be bringing something too dangerous for them to handle they try to shut it down before whatever it is appears. Just before the wormhole closes a man in his mid 40's comes tumbling out. It's Quinn Mallory! But, he's lost his memory of the last X years (we know it was the New Gods For Old nanoprobes, but he doesn't) but he remembers traveling with the original group and goes sliding to find them, accompanied by the students and the accidental addition of a random passerby.
His memory can be cut off at The Guardian, or any other point along the way as needed. It doesn't even need to be explained to the audience as long as it's made clear it is not a side effect of sliding. If Maggie is being used he can remember through Roads Taken and the repeat of the accidental passerby can be skipped. If Diana is being used he can remember through New Gods For Old.