If he had said only that and didn't use his apparatus setup to back up his claim, most people who believe in the HHO/water-powered internal combustion engine fallacy would simply say he's full of shit and it does really, really work for the reals guize. He had to show it for real and avoid saying it directly so that the idiots wouldn't know he just debunked their claims.

Maybe. Contrary to what people here frequently say, this isn't the technology used by that guy who claimed to have run his car on water.

But yet, HHO for general purpose engines is a dumb idea. As he confirmed, the improvement in combustion efficiency is maybe a break even with the work required to produce the HHO in the first place.