Question about Black Widow and Loki in "The Avengers" [SPOILERS]

[Danger Loud Prince]

Ah, who am I kidding? We've all seen it already, but I tagged it as spoilers just in case some of the select few of you haven't seen it yet.

Anyway, am I the only one who got confused with the interrogation scene between Black Widow and Loki? (I'm guessing most of the reply will be, "yes, yes you are"). The part where:
Black Widow: You monster.
Loki: No, it's you who brought the monster.
Black Widow: So, Banner? That's your play? <Alerting the others about Loki's plan> Thank you...for your cooperation.
And then everyone is cheering at how awesomely smart Black Widow is, while Loki looks like a complete and utter fool. Wait, what? How did that happen?

Of course the movie reveals that it is Loki's plan to use the Hulk against the others, but how did Black Widow know that for sure from that little dialogue above? Even if Loki doesn't have anything to do with the Hulk, replying "you monster" with "No, it's you who brought the monster" is an obvious smartass reply. He's simply stating the fact that, yes, they do brought the monster. How does that explain everything about Loki's going to use the Hulk as a part of his masterplan?

From the way the dialogue works, Black Widow can bait him with anything aside from "monster", and Loki will simply turn it back to her. Anything:

Black Widow: You asshole jerk!
Loki: No, it's you who brought the asshole jerk.
Black Widow: So, Stark? That's your play?

Black Widow: You're such an old man.
Loki: No, it's you who brought the old man.
Black Widow: So, Rogers? That's your play?

Black Widow: You spoiled brat!
Loki: No, it's you who brought the spoiled brat.
Black Widow: So, Thor? That's your play?

Black Widow: You're useless...
Loki: No, it's you who brought the useless.
Black Widow: So, Barton? That's your play?

Black Widow: You motherfucker!
Loki: No, it's you who brought the motherfucker.
Black Widow: So, Fury? That's your play?

Black Widow: <Admiring his long hair> You're such a pretty girl.
Loki: No, it's you who brought the pretty girl.
Black Widow: So, Hill? That's your play?

Black Widow: You...are so awesome.
Loki: No, it's you who brought the awesome one.
Black Widow: So, Coulson? That's your play?

In that way, everyone can be the "key" in Loki's plan. There's no certainty in that banter. Black Widow simply picked the "monster" number and went along with it, somehow correctly assumed that she won the jackpot lottery in the sea of endless other possibilities.
So, really, other than it being a lucky guess that's somehow true for plot reasons, how does that "interrogation" scene work in pinpointing that the Hulk is really the only one that Loki is after, exactly?

[Kalen O.]

Because of how Loki responded. It wasn't 'it was you [SHIELD] who brought the monster', it was 'you [Widow] who brought the monster.' Widow brought the Hulk in personally. It was a dig directly at her, not SHIELD or humans in general.

[Brad Barton]

Because of how Loki responded. It wasn't 'it was you [SHIELD] who brought the monster', it was 'you [Widow] who brought the monster.' Widow brought the Hulk in personally. It was a dig directly at her, not SHIELD or humans in general.

That's got nothing to do with what he's asking.

OP: She knew because it's her job to read the person she's interrogating. Maybe it had to do with body language, eye/facial movement, tone of voice, what was said and how he said it, etc. -- good interrogators read all that stuff. That plus it was in the script.

[Superbeast]

That's got nothing to do with what he's asking.

OP: She knew because it's her job to read the person she's interrogating. Maybe it had to do with body language, eye/facial movement, tone of voice, what was said and how he said it, etc. -- good interrogators read all that stuff. That plus it was in the script.

Um.... yes it does. Loki said Widow brought the monster and in this instance she did, she brought Banner in from his hideaway in India. It's clear as day just as Kalen O. said, Loki had insulted Widow and was still addressing her personally.

[kalorama]

Context is everything. Their conversation isn't just about those lines the OP summarized (and I'm pretty sure he left out some nuances in the actual dialogue in their exchange). She made her conclusions based on the entirety of their back and forth.

[RockinRobin182]

Yeah, it wasn't like she ran up to him and called him a name. She was extracting information the entire time. It's her job. She has a very specific skill set, after all. Also, Hawkeye wasn't useless...