It's pretty realistic. Look at statistics yourself. Women are predominately raped by an acquaintance (IIRC 7/10 women), and they sometimes go along with it for fear of further violence and exposure.
She doesn't fight back after the initial scream because of what's called "tonic immobility" or 'freeze response'. Simply put she's too scared to do anything. This is where she starts rationalizing the events.
In this case she doesn't say anything because her friend believes she's finally found 'The one' and doesn't want to ruin that. She's also afraid of losing her only friend.
Her comments to the student are her projecting how she feels about men. How they're a disgusting corrupting influence.