Well, on every other case Google Trands stats for websites have been very, very accurate (within 10% absolute real visits stats), so I’d guess there can’t be at least that huge of an error there. Other statistic sites also show same kind of results as presented by “Stupid” above.
What comes to CAP, I believe the numbers shown at Google Trends based on the forum traffic numbers visible to everyone in the bottom of the forums. The fact that G&C is more general site doesn’t mean that it attracts more visits automatically.