When Mac and Jack are remembering the time where Murdoc set them all up at the junkyard, Pete and Mac are shown in the crushed taxi cab. You can hear Pete shouting, "It's Murdoc!!" as the crushed cab is lifted away. However, in the original episode (Season 2 episode 18, Partners), they didn't find out that Murdoc had abducted them until the cab was placed in a tractor trailer, and the tractor trailer had been driving for a while.
There is far more water spraying out of the gold-separator than was put into the tub to begin with; the tub contained mostly just moderately-wet mud, with very little added water.
Shots of an obviously sunny-weather environment are interspersed with the duller-lighted shots of the rainy day.
A mistake is listed that the propeller in the "clip" scene is not turning so the airplane was filmed in front of a green screen. In that previous episode they lost the left engine; the right engine propeller is spinning.