Ok, it was a goose egg, but it may not be his mistake.
This is one of the LED's, he showed and which you can buy on Ebay, which have a yellow color due to the phosphor coating, and as you can see no volts, (it produced about .02 initially then went to zero, even though l may have played a part in that since every human has .02 of a volt up to .05, which can affect results).
So l soldered about 5 on a circuit board, (Ebay also) and initially it was about .12, then when l released and tried again, .06 then the next day .01 then zero again. So like this guy the initial results are promising then it goes pear shaped.
But check this out, this was a very old LED, (clear) that generated more than a volt when l held it close to the lamp, so these really could be superior to a solar panel, but of course they are not available anymore.
So l don't believe that this guy is scamming us, more of the case he built one tested it and took that as the result, or it is more likely these LED's build up a charge over time, and like capacitors discharge quickly.
So fun but no free energy, at least not yet, or the Tesla circuit is still the one to beat.