While I don't agree that you should have been kicked, you should have helped damage.
nothing in that, and most pre-50 dungeons, is going to take you by suprise. You can max heal in like 3 cures. With cleric stance being instant cast off the GCD, there's no reason not to DPS. I earnestly suggest you learn to stance dance. Most high level dungeons are pulled very large, where holy is a Godsend.