I was in a clockwork where one of the guys unlocked a "hard" section (marked by a red skull). Three of us went in and stepped on the party button. The fourth one wasn't in the mood for a hard section, so he didn't join us. We waited several minutes, hoping he would get bored and leave, but instead after a few minutes I got a loading screen and found myself all alone surrounded by a swarm of enemies without the rest of my party.
I'm not really sure what happened to cause this situation, but it was fatal. I don't know if I was kicked from the party or if he quit and we got shattered, but that's not the proper way for the game to handle the situation.
When the party leader will not play along with the rest of the party, there needs to be a way for the rest of the folks to continue enjoying the game without the rebel.
Also, there needs to be a way to let the rest of the party continue on without you at a rest stop (level 4, level 8, and I'm sure there are more). I'd like to be able to take the time to browse the vendors without wasting the time of my party mates.
Sounds like he kicked you. The only way to leave a party OF YOUR OWN ACCORD forces you to return to town, and right now there is absolutely NO way to deal with an uncooperative, inconsiderate, or even disconnected party leader (in the case of D/C it takes a VERY long time before the game will actually remove the person from the party automatically and let the rest of you continue)
Hopefully fixing this will be one the development team's highest priorities. I'd like to see it made so that in the event of EITHER being kicked OR choosing to leave a party yourself, a box would come up warning you of what's going on and giving you a few options. You could decide to remain on that dungeon by yourself (and then be asked your preference on allowing others to join you without invite), you could choose to automatically look for a different group that's in the same dungeon floor, OR you could choose to return to town.