And while communication is extremely important not everything needs to be turned into a huge, dramatic discussion or debate.

Some personality types feel differently.

Alice may know she'll be over it in a little while but starting a fight would lead to week-long estrangement.

Wait, what makes you think that Alice isn't trying to start a fight?

Incidentally, I offered these interpretations because they were the right answers in particular instances where a girlfriend said "nothing" when there obviously was something. At least these are plausible interpretations if I believe our later conversations about why she said "nothing". For these explanations the line by line interpretation is a little different-- she is upset enough that it is hard not to show it or perhaps she is torn about whether or not to show it. Perhaps she just wants Bob to feel a little bad about it. Perhaps Bob is more observing than we have so far given him credit for. When she yells at Bob in her last line she is yelling at him because she is annoyed by his instance on talking about it, not trying to be obvious about being hurt regarding the object-level matter.

Of course, this is only one possible reading of the situation; I just suspect that it's a bit closer to what Silas intended that most of the other readings.

I suspect Silas may have posted the comment without knowing or having a specific intended reading. Or he might be speaking as someone who has been a Bob in the past and genuinely isn't sure how to interpret Alice. I also think by rendering Alice's motivations explicit where making her too calculating. I suspect "nothing" often comes out just because it seems like the easiest thing to say at the moment not because of any well thought out strategic considerations.

I agree your interpretation is plausible, though.