I mean, if I were in his shoes I’d be pissed too, but if there’s a recording of the drawing showing that the actual numbers drawn and the listed numbers on the site were different, then it doesn’t sound like he’d have much of a case. It’s not like the website numbers were the only proof of what the winning numbers were that day.
Of course, Powerball could have generated some good will by paying him something (assuming they didn’t already try and he turned it down wanting the whole pot.)