Visible crew/equipment: When Bean is looking at the painting for the first time, he puts his hands on his hips. When he does, it lifts his jacket. When this happens you can see his mic pack clear as day. (00:39:50)
Visible crew/equipment: When Mr. Bean is in the boardroom of people discussing his fate at the beginning of the movie, there's one shot where you can see a cameraman's feet and a moving cable reflected in a shiny surface.
Visible crew/equipment: When Mr. Bean is in the operating room, there is a man standing behind a machine who is not dressed like the other surgeons.
Answer: In the context of the movie, the "damage" has already been done, so-to-speak... he's already in the shower with Bean. And since he's also in a big rush to get to the museum, he decides to just keep showering. (In a meta, behind-the-scenes sense, it's also just funnier for him to stay in the shower rather than get out and wait for Bean.)
TedStixon