Losing items in water isn't really a bug, that's just how it works. If you got sent back to your homestead you didn't die, you just got knocked out. If you died, your character would be gone. Also, as JeffGV said, you must have done something to aggro the turkey because they're not aggressive. They only attack if you attack them or someone else who attacked them hides behind you while the turkey takes a swing at them. In other words, there's no bug here just an unfortunate situation where you ended up losing your stuff.
My advice for seeking out a new place to settle is to hold off on buying the document until you've actually found the location you want to put your claim down on. Build a new leanto at the new location, port to Boston, buy the document, then port back to your new home and use the document immediately. Carrying it around is risky because unforeseen circumstances can come up that result in you dropping it.