Its easier than that. You can moderate by not allowing coments claiming something without proof or citation, and even more important not allowing personal attacks (unless they can clearly proof what they are saying about the other forum member is true).
The citations of Bruce's own words have been shown multiple times. What further proof would you like, exactly?
I have to say, if it wasn't for the fact that there is actual evidence behind these accusations, I'd be supporting the deletion argument right now. However, I also don't think this would have become an issue if there wasn't evidence, so the point is moot.