When bedding down for the night at the river, George's hands change position.
Crew or equipment visible
At the beginning, when George and Lennie are being chased, they are running alongside a train, then climbing inside. As they run, the shadow of the camera operator, wearing a cap, is clearly seen against a train car.
George and Lennie eat canned beans. The beans are heated before they open the cans, and they hold the cans barehanded.