Continuing through the writ:
Writ page 20: the National Post said Weaver's calling for replacement of the IPCC leadership, when he says he specifically told the reporter he's not. Again, a question of interview tapes or credibility. Here's a sidenote: I think the question of the National Post's accuracy as editors or as reporters can be brought into question as a general matter if they're going to defend themselves by asserting that they're accurate and Weaver's lying. Totally unrelated claims by people that the National Post had a pattern of misrepresenting them after being interviewed could be introduced as evidence. I think. Could make for some fun impeachment of witness credibility at open trial, and even more fun depositions, discovery of internal email/documents, etc.
Pp 20-21: Weaver says he's been consistently cautious about linking current weather events to global warming. This will be an interesting/potentially important. Defendants will say any description of a potential link, no matter how cautious, is sensationalizing, while a court that's had enough of the defendants might decide otherwise. For some reason, the public seems to listen to judges, so a court decision on this issue could be good PR. Also, the 'screams global warming' fake quote is a pretty good claim in that it seems tied to specific weather events and not the long term increase in temps.
I'm skipping some defamatory claims that were the same as above but repeated in later publications.
So that's the most interesting and important stuff, IMHO. One other thing I'll add is that Weaver's lawyer, Roger McConchie, appears to specialize in this field, so he's likely to get good representation. This could be very interesting.