I don't quite understand why Rory lost her ability to talk with Jess. Before they were together she could say whatever she wanted to him but afterwards she shut-down and stopped expressing her feelings to him. Yes, he should've called but when he didn't why didn't she just call him? He was being complacent and she was playing games. It was all a bit silly, really.
No matter how much you've moved past someone and how happy you are in your crrent situation, it is rarely easy to see someone you loved, happy with someone else. Being that Rory was young and it really hadn't been a long time since they split, it was always going to be uncomfortable.
In rory's attemtp to "not be that girl" she actually became that girl. By saying 'forget him' and going to the hockey game alone she was allowing herself to be 'that girl', even though she thought she wasn't. Not being 'that girl' meant calling him up, asking what was going on and telling him why she was angry at him. It seems cowardly to leave a message on an answering machine. Why can't she just tell him?