MORE VARIATIONS ON A THEME, WITH SPOILERS, OF COURSE
On repeat viewings of Brian De Palma's Mission: Impossible, the viewer now knows that Claire knows that Jim Phelps is alive. Armed with this knowledge, Claire's line to Ethan in the scene above -- "I want to get the son of a bitch who did this" -- sounds suspiciously scripted by Jim "I prefer the theater" Phelps himself. Phelps, in fact, will refer to that "son of a bitch" in his own meeting with Ethan later, in London.
In that meeting, we see a variation of the meeting in Body Double between Jake Scully and Sam Bouchard in the bar, which itself is a variation of the date between Jon and Judy in Hi, Mom!. In each of those previous scenes, a person (Jon in Hi, Mom! and Sam in Body Double) is attempting to manipulate the person they are speaking with through lies and improvisation.
In the case of Mission: Impossible, however, Ethan is not so easily duped, and Jim Phelps knows it. In fact, as much as Jim works from his own script that Kittridge was the mole, he watches Ethan intently to see if he is buying it. Ethan is also watching intently, because as soon as Jim Phelps tries to tell him that Kittridge is the mole, Ethan knows that none of it adds up. In his mind, he plays out the only scenario that seems to make sense, even is acting for Jim as if he believes his lie about Kittridge.
Martin Scorsese had a very similar dynamic in play in his 1991 remake of Cape Fear, a discussion that is punctuated by a hilarious cut to Nick Nolte forced to sleep on the couch. And to bring it all back home, the son-of-a-bitch being discussed in the Scorsese film is Robert De Niro. See it all below: