Taken from FoH, who took it from the official forums.

This week i ran BWL for my guild. During the RG fight i died and released along with several others Before RG was dead. once RG was dead i got a rez and dished out the loot. we cleared to the broodlord and called it for the night.

i later zoned in to BWL while in a UBRS raid and RG was back up. I WAS NOT SAVED TO THE INSTANCE.
i freaked out for a sec thinking we had to reclear. i then found someone who was still alive when RG died and made them raid leader.Then I zoned in to BWL and became saved to the instance.

also as where i was raid leader and not saved to the instance everyone who joined the raid after RG did NOT get saved.

I’ll break this down:
IF your raid leader dies and is released when RG dies and he/she will not get saved to the instance. every one who is not in the zone and dead will not be saved either but they can all still loot RG.

And here’s the answer from the GM: After some research it appears the issue you are having may be related to your User Interface (UI).

Got it? Now go exploit the hell out of it, for Blizzard it’s a problem of the UI.

Btw, as written in the comments, all the annoying changes to the reset timers of the instances were an attempt to solve various other exploits. It seems they have opened the way to bigger ones. Good work :)

Also remember that they disabled the /bug command right at launch so you could send your bug reports right to the GMs. Enjoy.