Originally Posted by Blizzard (Blue Tracker)
This did not appear to be a bug at first, but with all of the QQ about earning the mount from other players they suspended it.
No, it was fixed because the drop rate was never intended.

For them this was a brand new encounter, why take that away from them?
I'm not entirely certain how fixing an unintended drop rate for a single item takes the encounter away from anyone.

My understanding is that it is a guaranteed drop
That is currently for heroic version.

Will I be suspended/banned for winning a mount I had no idea was bugged? I know it probably won't happen, I would love a blue to chime in on this.
I can't say for certain but as I understand it, obtaining the mount required no exploitation. The drop rate should be fixed now. Additional actions would seem unlikely.