Visible crew/equipment: During Moya's attempt to land on the planet's bog-filled surface, in the close-up of Rygel as he begs for somebody to help tie him down, we can see Rygel's puppeteer, who's wearing eyeglasses and a cap, behind Rygel.
Visible crew/equipment: While on the planet, when Crichton is talking with Lyneea about the military not being very compassionate and Crichton says, "No, militaries rarely are": when it cuts back to Lyneea we can see the shadow from the camera moving on her. (00:27:55)
Visible crew/equipment: After they all take turns peering into the triangular hatchway, Pilot silences the paddac beacon's siren, and when the DRD zooms into the compartment in the shot from within the room we can see a cable behind the DRD.
Chosen answer: It's never explained. John mentions a theory that his less technologically developed craft simply interferes with the wormhole less than the "superior" Vipers, but they never make a concrete determination on that point. But we also have to take into account the fact that Moya traverses wormholes with no ill effect as well.
Garlonuss ★