Why did I get penalized for this?

[Nicobo]

We were in Cutter's Cry and things weren't going very well. Wipe once at the first boss, and 2 wipes at the 2nd. Healer decides to leave. I figure there's no point in staying, so I leave right after. Yet, I had a 30 minute penalty.

Wondering if the healer was left by offline? ^^;