Rory had other people to call
When Rory goes on that awful date with Graham from Yale. He is with his buddy's who drink a ton doing a pub crawl, he is talking sports with those guys and their designated driver is drunk. Funny thing is that Emily sets them up thinking this guy is a total gentleman, clearly she knew little about him as a college freshman. Anyways Rory obviously doesn't want to die in car accident with those morons so she calls Dean to rescue her as she is stranded with no money at the bar in a dangerous neighborhood.
She calls Dean and says she didn't know who else to call. Like he was the only person Rory could ask to come pick her up at a bar in New Haven? I know Lorelai and Luke were at Liz's wedding, although this was sort of an emergency...but she could of called Lane, Richard (unless he was away), Emily, Marty, Paris (although I believe she was gone already...), Doyle, Sookie/Jackson, even Chris...there were other people to call. Plus, it's not like she had anything to be embarrassed over. She just needed a ride home. I get that at that point they were supposed to be friends and she didn't have a lot of male friends to call to come help her out in a bad situation...but it didn't have to be Dean. I know this was just a way to get them closer together. Rory however brings up the important point that as a married man, he shouldn't be in a position to come and get her alone and to hang out for a while. Not appropriate.