É uma mosca MAS, na verdade, ela não entra na boca dele.
Aparentemente, de acordo com Paul Freeman, que interpretou Belloq, alguns quadros foram cortados do filme em que a mosca voou para longe.
Q: Can you tell us something about that, and working with the most famous fly in the world?
PF: Ah, yes. I don’t think anybody noticed it during the shoot, there wasn’t any hilarity at that point in the film, and I think if you look at it carefully, if you freeze the frame around that point, you’ll see that actually some frames are missing.
Q: Yeah, I think I noticed that, just a little too jerky.
PF: Yeah, I think they just took out a couple of frames when the fly flew off, just to make the joke. I got a very nice review from Pauline Kayland who noted what a devoted actor I was to go through it, with eating the fly and all.