In the party scene, when Michael (out of drag) meets Julie and lays "the line" on her, she throws a drink in his face. The drink hits the back of the man behind them. The man jumps, but doesn't turn around. When Michael turns to dry his face on the man's coat, the coat is dry - and Julie's glass still has champagne in it.
In the scene where George Fields and Michael Dorsey are arguing in George's office about Michael's being difficult to work with, the pen in George's hand and on his desk disappears between scene cuts consistently.
When Jessica Lange throws a drink in Dustin Hoffman's face, the drink can be seen splattered over the back of the man standing behind Hoffman. In the next scene, Hoffman walks up to this man and uses the back of the man's suit jacket to dry off his face. The jacket is now clearly dry.
The airborne panning view of midtown Manhattan (a transition shot after the montage of Dorothy's magazine photo-shoots, filmed above Union Square) is stock footage from the early 1970's or perhaps earlier; at least one skyscraper completed by 1975 is missing (the One UN Plaza towers).