Go to the scene where Osmosis Jones and Drix return back to the police department (when the Mayor, the Police Chief and Leah are waiting for them) and listen very carefully.

When Osmosis enters the door, he very quickly says, "Hey there, Brandy...I mean Leah." Brandy is the name of the actress who does the character's voice, but the character is named Leah.

Audio slip-ups are pretty rare, so I was surprised to hear this one. But I swear on my grave it's there.