Continuity mistake: When Derek Zoolander is being interviewed by Mugatu for the first time, when Mugatu's assistant brings him his drink and Mugatu spits it out you can see the drink all over the top of his mouth. Then you see him right away after that and it is gone. (00:27:10)
Factual error: There is one scene towards the end when Matilda is talking to her assistant and two clocks showing the times of Tokyo and Hong Kong are visible on the wall behind. In reality Tokyo is one hour ahead of Hong Kong, but the clock clearly shows Hong Kong as one hour ahead of Tokyo. The Frankfurt clock is also an hour slow, assuming the Chicago clock is the correct one. (01:11:05)
Continuity mistake: When Matilda is being thrown out of the day spa and Katinka tell's K-mart about her outfit, the door behind her is open. The very next shot of Katinka, the door is shut. (00:32:45)
Continuity mistake: When Derrick and Matilda arrive at Hansel's, watch Hansel's turquoise necklace. It goes inside and outside his shirt a couple of times, while talking at the door. (00:54:55)
Continuity mistake: When Mugatu leaves from behind the desk to show Derek the model, the chair Mugatu spins does an extra 180 turn. The chair front is still facing the wall. (00:27:35)
Continuity mistake: In the scene where Mugatu is talking to Mr. Ballstein, Todd gives Mugatu the phone to talk to Mr. Ballstein. The camera cuts to a shot where you see Mr. Ballstein in the bathroom. In the shot after that, Todd and Mugatu have switched places. (00:22:30)
Continuity mistake: When David Bowie steps forward to Hansel and Derek, he grabs his hands around their shoulders. As the shot changes from Bowie's face to Hansel's, his hand is gone from Hansel's shoulder, but after the shot turns to Derek and then back to the view of the three of them as it was from the beginning, his hand is back. There's a shot of the back of Hansel's neck with no hand, the angle changes to the front again and the hand is back. (00:43:40)
Answer: It was raining and it was that water from before just running down the semi-sloped road.