As Tiffany and Kris start driving school, Tiffany's sleeves are rolled up. As the truck approaches them they are full length, but rolled up again when the truck stops.
Tiffany's shirt becomes buttoned up one more button when she and the moonshiner exchange places in the truck. Once the sheriff departs the top button returns to its original position one button lower.
When Kelly inquires with the mechanic, she is sporting bangs. The next frame, when she goes investigate in the office, her bangs are gone and completely swept to either side of her forehead.
When the Angel's are getting the brakes repaired it is revealed that the air line developed a hole and the air escaped. When air brakes lose their pressure, they are automatically applied thereby stopping the rig. So if what the mechanic said was true, that rig would have been locked down with the brakes fully applied, not rolling freely like a runaway train. BH.
Although she isn't shown driving it until her twelfth episode (Cruising Angels (1979)), Sabrina's orange Pinto - seen parked outside the Townsend Agency building - was indeed used by her replacement, Tiffany Welles. You'd think after three years the company could afford a nicer - and less conspicuous - car. Perhaps the fault lies with the notoriously stingy Bosley.
When Tiffany is driving the truck and the brakes go out, the gauges shown on the dashboard are from a White Motor Company truck. The Angels are not driving a truck produced by White. They are always seen driving an International Transtar.