Pretty sure this is a bug (a pretty annoying one as well), but when go back to the distillery to give Slackjaw the audiograph I suddenly become an enemy and he starts attacking me and the objective fails. this meant that I can no longer deal with the Pendleton's in a non lethal way. I was doing this mission without killing anyone, so I definately didn't kill any of his thugs or anything. What gives? Anyone else experience this?

Here's a thread dealing with identical (?) problem..... perhaps it can help you.

http://www.gamesas.com/topic/1416003-slackjaw-attacking-me-without-warning/