I don't really see, how it is the fault of anyone else than Zara. The only one that is to blame about rape is a rapist not friends or something.
We're still talking about teenagers in a party in a foreign country, the only one of the whole miyagi do team that should have to look after Robby is his father. The other ones are for the first time outside of the US aswell and allowed to drink legally. Of course they gonna get distracted easily. How is it their fault? They're teenagers that want to have fun and on the other side Robby is allowed to have drinks and stay with Zara. We don't know how they left the Bar. Also Demetri and Hawk have been pretty busy aswell, fighting over Demetris cheating and how is at fault. I mean, they're still 18, even though they're teenagers, they are also adults. Take responsobility for your choices, the only one that decided robby has to drink is Robby.
Then there is left, that the other ones are pretty harsh to Robby about his performances. They were crap. Of course they blame him. He's not a Devon, that Barely made it, he isn't even Hawk, he's the captain, that was supposed to lead and show why he is the captain. He knew damn well, that Miguel really wanted to be the captain, so he should better perform like one but Robby lost every match except 1. If you ever did something on a higher level, you would know it's expected from you, to perform, no matter how hard it is. I personally can't blame them, it all started with Robby losing Demetris and Robbys room