It's moments like these that I wish I had fraps or would remember to take screenshots.
We just finished a (mostly) guild run of the above, and it bugged out on the last boss. It was my first time there in Heroic mode, and it bugged the one time I did the instance on normal too.
One of our group didn't get the buff. Everybody else did, but after a couple of minutes I was the only person left alive. I'm an Unholy DK, so Death Strike isn't usually in my rotation, but I had a couple of runes available and PS and N(ecrotic) S were on cooldown, so I hit DS and WHOA! It healed me for over 300k.
I switched into Blood Presence and proceeded over the next 5 minutes to solo the crap out of tentacle guy :D
This was made even better because us guildies in the group were on Vent, and over those 5 minutes I'd got an "audience" of about 20 people :)
I'm putting this here in the hope that people will enjoy my little tale of triumph and relate their own, but I have a question too: Should I report this to Blizz? I'm sure they know of the bugging out, and I don't think it's really an exploit, but they probably didn't intend for this sort of thing to be possible either.