just spent too long trying to figure out who played mystery moreau hitter guy. there's an "airport traveller", uncredited, played by Ryan Noël who has a whole bunch of photos looking friendly and harmless and a demo reel that ditto, and a Joshua St. James who's credited as "Curtis", a name that doesn't appear in the transcript and thus probably the episode, which seemed promising up until I tracked him down to this (he had two bad imdb photos) and realised his nose and eyebrows were wrong.

also the hair, for both of them. it seems unlikely they'd have bothered with a pretty damn good wig for this role.

I am, I should admit, A Little Bad at faces, so at this point & on the basis that my investigative skills end at imdb, I'm giving up. though this has driven home that mystery moreau hitter guy has a very nice nose & eyebrows.

(just sharing my notes in case anyone else was inclined to go down this rabbithole.)

responding a year (and a half) late because it's been that kind of year (and a half) but thank you you were entirely right

I think the leverage commentary transcripts blog hadn't been updated to that point when this was posted, but it has now, so I went to have a look. the actor is indeed married to Kari Wuhrer and can be seen recognisable and smiling on his imdb, which is very strange! and the sniper character is referred to as "The Frenchman" by a few folks.

the really batshit thing, though? he's not credited as an actor for anything, but is listed as co-producer for Leverage seasons 4 and 5.

so there we go! I felt a little bad leaving this mystery unanswered, so thank you again @defiantly-whole, I'm very glad I can put this to rest.