On the island, Ivan bandages his hand after it gets injured. In the next shot, the bandage is on his other hand.
After the brothers fight early in the film, Vanya challenges Andrey to chase him and they go tearing off, presumably with Andrey trying to get his hands on Vanya. The ensuing chase is shown in several takes, with credits interposed, in one of the takes Andrey, Vanya is chasing Andrey, but when they get home Vanya is again running ahead.
When Ivan is sitting in the car, the camera pans around the car (before we see him grab the binoculars and begin to use them) - as it pans past the triangular car window you can see the camera reflected in it.