"Often wrong"? Really? By often, 50% more wrong than right or less? Or more? I can count on one hand the number of occasions I've found the documentation to be incorrect.
"Often" is a fuzzy term and it's used subjectively here. It doesn't mean "most of the documentation" (which would be the >50% goal post you're driving at). It simply means "a lot of the time $OP checks the docs". It might be the case that the only time they need to check the docs is for some of the more advanced features of PHP where errors are more likely to be found in the docs. While you could correctly argue "selection bias", it doesn't still take away from the OPs perspective that it often happens to him.