Why would it include the guys? They don't understand woman nature and "disappointment" feelings. Not to mention the language barrier.
And speaking about human nature, when two girls fight, it's not in the nature of a man to join in.
I don't know who would have said what and done what at exactly what time. IMO, an
escalation is very possible. You are coming from the viewpoint that 2 of these people are completely normal. yes, I agree, it doesn't make sense when you consider it with normal people. Normal people would not go and stab someone, either.
But if we look at the evidence as a whole, and we come to the conclusion that the participants of the assault and murder were Rudy, Amanda, and RS, then that means that all 3 are not normal people. Thus, you have 3 erratic people together,
something happened. Something happened.
I think SMK and I and others have laid out possible scenarios of how the escalation
could have occured. We do not know exactly what happened. Just like you don't know
exactly what happened with Rudy - was he in the bathroom, was Meredith home already, where did they first see each other in the house, was he on the toilet or somewhere else?
So for example you said, why did the guys join in? Well, we don't know who started the general teasing, if that's what happened. Maybe Amanda, maybe RS, maybe Rudy, maybe all 3 together. Maybe there was no argument at all in the beginning. Maybe like, I suggested, it could have been that they saw Meredith b/c she came into the kitchen, they asked her to join them, "come on, come on," she didn't want to....she goes back to her room. Amanda comes up with a "prank" to inject "life" into the party - "hey guys, let's go in there and (insert prank)." They do some prank, or do something to annoy Meredith, she gets annoyed, maybe she 'overreacts' then, hurts Amanda's feelings. Maybe she doesn't overreact then, maybe she doesn't react much, so Amanda, RS, and Rudy continue to pester her and annoy her.
I don't know exactly what happened, none of us do. I don't think the idea of an esclation is far-fetched at all.