#ep01x04

hi, anon!

for my money, susan isn't the surgical tech doug mentions, as even at that early point in show development, both the writers outside of the universe of the show and the characters inside of it knew that susan was a doctor and specifically an r2 in the emergency room, so if the writers had intended for doug to be referring to her, that's the terminology they would have had him use.

they also probably would've made him drop her name, as specifically identifying her that way would be the best cue to the audience, who were at this point still learning the characters, that marsan was a thing.

(which is definitely was, because the showrunners had written it as part of mark and susan’s initial character descriptions.)

that said, there is a very similar scene to this one from the pilot in episode 01x04 "hit and run" where doug directly asks mark if he's ever fantasized about susan, and mark confirms that he has ("so what? i'm a married man. doesn't mean i'm not allowed to speculate"), so even if the reference is not there in the pilot, it is there pretty much right out of the gate otherwise.

doug definitely knew before mark did that mark was in love with susan.