I think the reason Willow and Xander didn't wonna be alone with her, was cos they were scared they'd let all their anger out. they knew she had been through alot, and I think they tried to understand, but couldn't help being angry. And when Willow found Buffy trying to run away again, she just lost it. And then it started between everyone.
Giles has always been very understanding, not everyone can be like him. But I think he closes alot of his anger inside.
Some of you say that the gang haven't been as close since, but I think it's the other way around. if Xander and Willow hadn't let their feelings out, they could still be bottling their anger up inside of them. That's never healthy, and when people do that, it's always there, even though noone mentions it.
And I think they were also hurt by the fact that Buffy didn't come to them, she ran away instead. I don't think that episode made Buffy close her feelings more up, she's always been the type to wonna be alone with her feelings, and it often takes time before she tells her friends about things that worry her, and hurts her.
I think I understand them more because I know what it feels like to worry about someone you don't know where is. My bestfriend ran away twice, and the first time I had no idea where she was. I was worried sick, and I was angry at her for not letting me know where she was. And also for making her mother worry that much.
We don't know what happened with the gang that summer, there could be alot of reasons to why they were so angry, not only the fact that she didn't let them know where she was, and if she was ok, for months!
I understand Buffy's need to get away, but she could have picked up the phone to let them know she was alive!