man, he didnt have to go that far.... could have least been nice

Ouch...

I would have released a huge sigh of relief, maybe adding a 'thanks goodness', just to make her paranoid.

the first what she said was true, because she has said that, what first came to her mind.

She was implying to her friend that she was going to flirt etc with someone on the elevator. It wasn't true and she wished to free you of obligations. She basically used you to hang up on her friend. The wording was unimportant, don't feel bad about it.

Take the stairs next time.

Her wording was awkward and you probably just misunderstood what she meant. Her excuse for hanging up was "I want to flirt with this cute guy" but she didn't really, so that's why she told you she was lying so you didn't think she was flirting with you. You being cute or not cute didn't matter, but the fact that that excuse popped into her head means she probably thought you were cute, but not her type or something.

#8 You make me proud.

you should have just said. "you're not lying...you think i'm cute. Let's do something about this"