<p>I think you’re entitled to ask the company their thoughts on the matter. Just be honest with them. Tell them you’ve been offered something else and would rather do that, but that since you’ve already accepted their offer that you will honor the arrangement if it’s too late for them to find someone else.</p>
<p>The worst case scenario is that they insist you should work for them, and that’s not so bad, right? You wouldn’t have accepted if you didn’t want to do it. Odds are they’ll tell you that it’s fine and you can pursue your interests without even the possibility of developing a reputation in the community as fickle.</p>
<p>I’d be wary of relying on defamation laws to protect your reputation. As long as they’re telling the truth - which they can prove, of course - facts can have a funny way of reaching their destination. Also, as far as I know, blacklisting refers specifically to deliberate attempts to prevent employment, and deliberation may be difficult to prove. It’s all very tricky and the best way to maintain integrity isn’t by relying on laws which give people the benefit of the doubt, but by trying to make decisions which you can live with.</p>
<p>If you thought it was alright, would you be asking us?</p>