In the context, I feel that answer has everything needed. It's clear from the question that the OP knows how to check and change permissions, and that information is available elsewhere on the site (the chmod and permissions tag wikis even have some fairly helpful info I think)
Of course, you don't have that context in review unless you click the link, and I can see why you felt the answer needed expanding.
I usually click the link for context if I'm in any doubt (and then of course you find out it's an audit and pass ;) ) Even so, I failed an audit myself the other day because I tried to comment on a post (the context would not have stopped me - after failing the audit, I went ahead and left the same comment). I'm definitely not especially enlightened so I can't say me failing means it could happen to anyone, but I'm pretty sure it does happen to everyone occasionally, and although it feels bad, it is just bad luck sometimes as the system is not perfect, and you don't need to worry about the occasional one.
Thanks for all your careful reviewing :)