When Shaun is being washed in the basement, the Knit-O-Matic malfunctions and switches the setting from "Wash" to "Light Shave". After Wallace tells Gromit to do something, you can tell by the lights on the settings that the Knit-O-Matic is still programmed to "Wash". When we see Preston's point of view from where he is hiding a few seconds later, the Knit-O-Matic is once again programmed to "Light Shave".
When Gromit climbs up the ladder during the motorbike chase, he places the base in the sidecar. When he grabs the cables, Wallace grabs the base of the ladder as it rises; after they finish the spin, Wallace places the foot of the ladder in front of him.