I wish you were right, but you're not. For all the press about the "war for talent", there's never a good time to be a whistle-blower. Sometimes it is worth doing, because these kinds of stories are extremely common (read: there are a lot of bubble startups with shitty, unethical management) right now, but it's generally a risky move.
Our perspective: Josh is a hero who exposed a crappy, sloppily-managed startup after the executives moved to deprive him of a promised bonus.
Stereotypical HR perspective: Josh is a risk. He exposed an employer's "dirty laundry" over a trivial amount of money and "professionals just don't do that". Oh, and there's this thing about losing data in the last 2 weeks. Sounds like he fucked something up and was fired.
Sane, reasonable counterpoints: Josh was right to do what he did, because he probably prevented other people from getting screwed by this company. Also, we have no idea why the database problem occurred. Maybe he was working 14-hour days (it's common for shitbag startups to push people to put in 80 hours per week, and later use the low quality-- on account of the overtime and deadline pressure-- of what is produced as justification for canning them once the equity is worth something). Maybe he was badly trained. Who knows? It's just as likely that it's not his fault, and regarding the manner of his termination, who cares?
Not-unreasonable (but unfortunate) HR counterpoint: Sure, sure, but he's still riskier than this other guy who didn't expose an ex-employer and has identical credentials.
Of course unethical employers would hesitate to trust him but do you want to work for unethical employers?
I don't see this division as being as firm as one might like. Corporate "culture" is largely a fiction. Most companies have a mix of ethical and unethical people. Saying you wouldn't want to work for a 100-person company because there's one unethical person (or, for your example, a "sympathizer" with unethical people) in HR is short-sighted. No company is perfect, and if you insist only on working in companies where everyone is ethical and good, well... you'll have a hard time working for companies larger than about 10 people, including your own.
In a competitive market (which sort of exists in tech), those companies that exhibit bad judgement fail. You're really doing yourself a favor by not getting hired by them.
Frankly, I think any company that would behave as you describe would probably do this same shit all over again.
I'm not sure if this guy is a decent hire or not (possibly not), but my decision to hire him wouldn't be based upon this episode, it would be based upon whatever I could figure out about his abilities.