Complex sentence: To support this claim, he points out the actor is wearing a very large fake moustache and a hat, and when his moustache detached before the end of the film, he hid his face by an arm until the moustache was reattached.
Split into simpler sentences: To support this claim, he points out the actor is wearing a very large fake mustache and a hat. When his mustache became detached before the end of the film, he hid his face with an arm until the mustache was reattached.