Although I agree that everyone needs to watch out for low contrast type scenarios, I don't exactly see how this article exemplifies one in any way. Can you point out anything in particular?
WCAG 2.0 requires a contrast of 7:1 to reach AAA levels. [1]
you can test it yourself with a bunch of tools but I couldn't find link to results on any of them [2][3][4].
[1] http://www.w3.org/WAI/WCAG20/quickref/#qr-visual-audio-contr...
[2] http://webaim.org/resources/contrastchecker/