Continuity mistake: The credit has "Lucy Morgan " Later her name becomes "Moran", see the name plate on the desk.
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: When Donna confronts her mother about Ben Horne, she is asked to pass the peas. Her mother fills her plate with peas. Only a few sentences later Donna is asked again to pass the peas and her mother fills her plate again, without having eaten anything in between. (00:42:10 - 00:43:10)
Visible crew/equipment: A boom microphone is visible at the top of the screen during Leo Johnson's trial. (00:15:00)
Continuity mistake: Ben Horne's glasses are knocked off during his arrest at the Great Northern. No one picks them up, but when he is brought around the corner of his desk, he's wearing them again. (00:28:50 - 00:30:30)
Plot hole: In the season 1 finale, after they have brought James into the the station Cooper hands Truman a note and asked if he would investigate this. A few minutes later Truman comes back in with the coke that Bobby planted in James' gas tank. Cooper then asks James why he had coke in his gas tank. Cooper shouldn't know where the coke was found, Bobby never mentioned to Lucy where he put it and Truman never told Cooper where he found it.
Answer: The answer to pretty much any question beginning with "Has David Lynch ever explained _______?" is: no.