Given some of the stuff I've seen people happily put up on them (both male and female) I'm not really able to quantify what would count as a 'gaffe'.
Plus, the fact that men are less private with their data is not necessarily a privacy mistake. Regretting something afterwards is not the same as not wanting to reveal it beforehand. I've done quite a lot of things I regretted later that were bloody excellent at the time!
Seems to me this survey started with a very particular hypothesis, then 'analysed' the data to prove it. I'm sure Ben Goldacre would have many things to say about it.