Demetry's a good guy. He's stayed at my place before and has done workshops with my crew. He's an excellent instructor & practitioner and an overall nice guy.
For those that don't know... Furtry was actually an official alternate for the Canadian Olympic Wrestling Team. He has a plethora of experience in groundfighting from myriad of different systems.
I second Masterfingers comments on the quality teaching Furtry can provide. I don't know if a video of that event is available... but if it is... I'd seek it out.