She was hurt and said things that Lindsey really didn't deserve. She was bitchy. And yet I do understand why she did it. Not that I think it makes it right in any way, but I get it.
As for the comment on the ring, isn't that what many girls do? Find just about anything to make a comment about. Even if they have to lie, they want to diminish it. She was jealous, I think, that Lindsey was the one wearing the ring instead of her. So really it wasn't about the fact she suddenly stopped liking the ring, it's that she disliked the fact it wasn't on her finger.
But while I don't think she should have taken it out on Lindsey, I don't think she should have been a bitch to Lucas either. They broke up and he moved on. That hurts, but it happens.
Oh well, it all made for a good season in my opinion:P