When do you get saved to an instance (raid)?

Hello,

I was in a pug (ICC10), I died at the first encounter and I ended up leaving the raid mid fight. No cooldown or being saved to an instance, afterwards I joined a TOC25 and the leader changed it from 10 to 25 or vice versa (can't remember), and I automatically got CD'd on ICC10, could anyone explain me if it's a bug or something?

Thank you,

If you contribute in a fight in any raid or dungeon and you leave halfway through the boss fight you still get saved if the boss dies on that attempt. You could've encountered a bug where the save didn't show up or something of the sort, maybe you just missed seeing it in the saved dungeons list?