Continuity mistake: When James is talking to Evelyn Marsh after fixing her husband's car, Evelyn's hand jumps from her lap to the steering wheel between shots. (00:22:00)
Continuity mistake: When Mike Nelson asks Donna for help in dealing with Nadine, Donna's right hand is inside her locker, looking for something. It then mysteriously jumps to the top of the stack of books she has in her other hand. (00:12:45)
Answer: The answer to pretty much any question beginning with "Has David Lynch ever explained _______?" is: no.