More generally, "I wouldn't trust Wikipedia to give correct $TOPIC information. I've noticed they've been incorrect about this before."
Articles like the one under discussion would be a helluva lot more persuasive if they linked to some resources for their stats. The claims about vegetarianism struck me as clutching at straws just to be contrarian.
To clarify what I meant, for what it's worth, I have personally experienced Wikipedia to be inaccurate with nutritional data, and that's something I've spent a deal of time looking at.
http://www.sainsburys.co.uk/groceries/index.jsp
Wolfram Alpha agrees, for what it's worth:
http://www.wolframalpha.com/input/?i=kidney+bean+100g
I wouldn't trust Wikipedia to give correct nutritional information. I've noticed they've been incorrect about this before.