For one or two shots, Rubin's shoe faces the wrong way as it spins towards Rula and Jimbo's car.
In one shot when Ed points towards Rubin (the camera behind Ed) as Rubin is walking up the desert hill with his cooler, there's a jet-stream visible in the blue sky beyond Rubin (which looks intentional). Three seconds later, after cutting back from a closeup of Rubin, the jet-stream is gone.