Being kicked for no reason?

Hi, so I’m a little confused. I’ve recently started playing Cataclysm Classic and got a Shaman to 85. I started doing Heroic Dungeons as a way to earn JP and VP. However, during a dungeon, I was removed for no reason. I stated that I was quickly handing in a quest in the dungeon and when I caught up with them, they kicked me. Now, my character isn’t the strongest, as I wasn’t doing dungeons as I leveled, but surely that can’t be a reason right? For a heroic dungeon? We hadn’t wiped, only one of us had died, and I was keeping up with the damage a fair bit.

I just don’t understand what I did wrong? Or if they’re in the wrong for doing that. Or if this is just how WoW’s community is with returning players or casual players. The guys in the dungeons were raid geared while I have only gotten loot from a few HC and some things off the Auction house.