Yes, of course, not done that many times since luckily! We can all pick out bad bets from our past, if you can't then you're only fooling yourself! Acknowledging bad bets is part of developing yourself as a punter and turning you into a winning punter long term. Like when I backed World Domination for the Derby and you backed Sajjhaa for the Oaks....
I do think this scenario was different to Beauty Parlour though, I just couldn't see any resemblance of evidence pre-race which suggested Kingman should be significantly shorter than Night of Thunder on all known form. The subsequent result is irrelevant to this debate really.
Odds on favourites will always be less value due to the margins involved, you're much more likely to find ricks at 10/1+ than at odds on due to the way the market is formed and the money traded, a bit like Apple's share price is a lot less likely to be wrong than some obscure Latvian telcoms company or a Nevada start up for example.