In the scene where Richard Dreyfus is stopped at the R.R. crossing and looks out of his window to see the bright lights shinning on him, the right side of his face is exposed to the light. Later everyone notices that his face is burnt, however it is on the left side of his face.
When Dreyfuss sticks his head out of the window, he shields the right side of his face and only the left side is in the light. Thus, only his left side is burnt!!!