I think the argument is that before the passage of 1284, there was a lot of money changing hands. I don't believe they cover actual figures in this article, but it does talk about some of the organizational spending: Medical marijuana advocacy group implodes on the cusp of victory - Denver News - The Latest Word

I certainly wouldn't say the contributions in these races are indicative of "big money" in the industry being thrown around. Maybe that's because so many felt burned by what 1284 became by the time of passage?