Frankly it wouldn't surprise me that Google was somehow using Wikipedia links in some way, but if they were it'd have to be a dark secret.
One of many dark secrets, no doubt. Search engines have no obligation to play by the rules they make public.
You might both be right about that. But just as a funny note, there have been two recent videos on the googlewebmaster channel on youtube where Matt Cutts is basically begging wikipedia to makes SOME of their links do-follow, so that google can use wikipedia for page rank.
He even goes on to suggest to wikipedia about HOW they should go about deciding if a link should be no-followed or not.
I wonder how the team at google would feel if wikipedia editors started giving google advice on how to rank search results...