What confuses me is that he says sprouts generate enzymes that prevent you from digesting nutrients... But fasting for 3-5 days would not kill you...
Unless he meant eating only sprouts but drinking no water either... I think this is probably what he meant.
Either way, I don't think it's meaningless that you only made it 1 day on only sprouts
When I was doing a vegan diet back in 2010, I regularly ate raw sprouts but I found I could only handle a small amount and mixed with other foods, and even then they tasted like soap.
I wouldn't necessarily put a lot of emphasis on what "sproutarians" claim, being that I know of several people who claim to live on sungazing or just air ("breatharians"). I knew one of them personally and he got very thin on his "breatharian" lifestyle. He was faking it to some of his friends and when they weren't there, he'd pig out on high calorie foods.