How can I bring this to the attention of a GM?

[Saneko-ragnaros (Saneko)]

This has been answered here:

Hey general : little help

Email hacks@blizzard.com explaining clearly what happened and attaching the video if you think it will help them. They will investigate and if it is some sort of glitch/cheating they’ll send it on to be fixed. (You probably won’t get a response unless they need more information).