I don't think a higher IQ would of helped on this one, or the hundreds who fall each year
You are right on that one, common sense would have, even people with a high IQ don't necessarily have that.
Walking around of a leaf covered roof, with no idea what is underneath, whether there are hazards or if the roof would have been structurally sound should have rang alarm bells everywhere!
This is about safely accessing a roof and working safely off of it and the HSE point of view on this.
This flat roof malarkey really reminds me of Ionic's zero ppb marketing, but then in H&S!!