Devon, this is a great question. Generally when one gets exposed, they stay exposed. I'm thinking of guys like Chuck Davey, White Lightning Brown, Jose Baret, Shawn O'Sullivan, et al. It's a toughie thinking of ones who basically 'showed them' by coming back successfully and showing that they weren't all window dressing. The closest example I can come up was one who was not so much a hype job as he had a chink in the armor exposed. And that was Tony Mundine. Tony came undone as the #1 contender when he was taken out by Bennie Briscoe in 5 rounds. The boxing world was in a state of shock. It was an impediment in his career going forward, but still Tony had heart and kept plugging away with the old problem arising again here and there. But he did have his levels of success also. After the Briscoe debacle, he still went on to fight for the world middleweight title, fight an eliminator for the world cruiserweight title, win the Commonwealth light heavyweight title and beat Mustafa Wassaja, Hocine Tafer, Bunny Johnson, Pete McIntyre and Nate Collins along the way. Again, a tough question and one that really gets one thinking.
Barrera? Two unavenged losses to Junior Jones, but went on to have a great career. I suppose you can say that Leonard exposed Hearns in a way, but he'd go on to greatness as well. Louis by Schmeling, maybe.
Wlad Klitschko, an Olympic gold medalist and the perfect physical specimen representing the new, super heavyweight. Considered the heir-apparent to Lennox Lewis, with his loss to Purrity written off as learning experience... And then he gets blitzed by Sanders in 2 rounds, ktfo by Brewster in a fight that should’ve left Brewster near dead, has a bizarre fight with DaVaryl Williamson and gets knocked down 3 times by Peters. Now be honest- did you see him being dominant for the next 10 years after all that? Not only not losing fights, but not really even losing too many rounds. He wound up posting ATG numbers comparable to Louis and Holmes. I didn’t see that coming.
The fact that they came back and went on to have highly successful careers sort of undermines the notion they were hype jobs at all - they had setback defeats and in Barrera's case, I think it fits the bill a bit better than Hearns. In actual fact, one of the other guys you mentioned, Junior Jones might be a better example. He won a world title, then looked to have been exposed by an average contender and then came back to have career best wins over Barrera. I'd still hesitate to call Jones a hype job, though. I think that's the difficulty with answering this question. A fighter may lose unexpectedly but the act of coming back after defeat and doing well subsequently undermines the idea they were hype jobs in the first place.
LOL, I missed the question in the first post of the thread - just read the title. My answer looks especially funny considering the fact that Micahle Grant was stopped in 43 seconds in his comeback fight and had very pedestrian career after that
Shannon Briggs. He was being hyped as the next heavyweight prospect from the same area as Tyson and Bowe. He was arohnd 25-0 when he fought on HBO's great night of the young heavyweights (they should of tried to make that an annual thing) and was KOd by Darrol Wilson. He ended up rebounding and winning a decision against Foreman (though many had him losing) and putting up an entertaining effort against Lennox Lewis. Then around 8 years later he wins the WBO heavyweight title kind of out of the blue by KOing Liakovich.
Billy Backus - had a very good amateur pedigree before going pro, fighting in AAU and regional Olympic Trials. But of course, that's not what made him hyped going pro. It was the fact that he was Carmen Basilio's nephew that all eyeballs were on him. Unfortunately, as a young husband and Dad he was trying to be a fighter as well as putting food on the table working construction. His boxing suffered, he went 8-7-3 and 'retired' to working full-time. However, when he got laid off, he turned back to boxing after 2 1/2 years just to supplement unemployment. But now putting 100% to boxing he went on a tear over the next few years beating Percy Pugh, Johnny Brooks and Vince Shomo before beating the #1 contender Manny Gonzalez, which got him his title shot against Jose Napoles. Now that's a turnaround.