no lies, man. came straight from aykroyd in several old interviews. i don't have time to find any links, but he said murray agreed to work “a few days on it”… and this is loosely confirmed by the “venkman” cameo in the first draft of HELLBENT. of course, aykroyd mentioned in a TIME interview last year that he was never able to get murray to read any of the scripts.

Right, but I never considered that “working a few days on it” actually committing to the project, I guess…

i was thinking more of bill murray, GB film-rights holder, as opposed to bill murray, actor.

Ahhh yes this is true. But then again, Bill Murray rights holder, was basically just always lied about. Dan always insisted that wasn't the problem until finally he came out and said it…

i'm pretty sure when aykroyd started hinting that murray was the culprit, he said murray had agreed at one point. i'll have to go back through some old mags to find the interview….

Bill Murray is just one of those guys that doesn't give straight answers. Ackroyd has mentioned in the Time article that Bill makes business discussions a very hard thing to discuss, and talking to him as a friend is more the only way to speak to him. He's stated in that interview that he doesn't even think Bill read the GB3 script at all. Ivan Reitman stated back then during the possiblitiy of GB3, that when speaking about Bill, he's a guy that “changes his tune alot” and isn't one that gives an immediate answer.
So I do think Murray agreed to do GB3 at one point, but may have actually said he'd do it for a few days or whatever. But then had a change of heart. Dan has again stated that its something Bill thinks should just stay the way it is, and not explore that concept again. Leave it alone from their past and let the two films stand alone. From what I remember about GB3's rumors, I think this assumption may be the best way to put it.