Continuity mistake: In the hotel lobby, the chair that Leland knocks over switches between shots between lying on its side and on its back.
Continuity mistake: After Leland is pulled over by the police, he goes to open the boot of his car, and he is wearing dark gloves. When he rummages in his golf bag containing the body for a golf club, he is wearing no gloves. Then he holds the club in the air to show Cooper and the gloves are back again.
Continuity mistake: The amount and pattern of the golf balls on the Palmers' living room floor changes between shots.
Answer: The answer to pretty much any question beginning with "Has David Lynch ever explained _______?" is: no.