Audio problem: When Jerry uses the elevator, the voice of the computer reads out the floors as "twenty-third floor, fourth floor, fifth floor" etc, missing out the "twenty-" prefix until the 29th floor. The DVD subtitles list these numbers with their prefix, so this was not intentional. (00:21:10)
Audio problem: Scully asks the deputy if the vests are necessary and he replies in the same scene. His mouth is way off from his reply. It's likely this is because the show was shown on 4:3 aspect ratio televisions at the time, and he would simply not be visible. Because the show was shot in 16:9, he is very much visible on modern televisions and the mistake is incredibly obvious.