Audio problem: When Walter is destroying the expensive sports car, the owner comes out of his house to stop him. You hear him screaming, but his mouth is not moving. (01:12:40)
Audio problem: When the Malibu Police Chief throws his coffee mug at The Dude you hear it glance off his forehead but never hear it hit the floor. Even if it somehow didn't break, it's a solid floor (not carpeted) so the impact would've made a noise.
Answer: Themmen plays a background bowler in pretty much all of the bowling scenes. I don't know if this is necessarily worth a credit, but I guess his agent disagrees with me.