He also frequently said he was the world's worst coder, so...
If we are describing human conversation, then - um - I call bullshit. If you give advice, you most certainly imply (for a suitably non-formal definition of 'imply') authority, knowledge, etc. about the matter you give advice on.
Your example - or the way you spin it out - is very odd. If you give directions to some coffee shop, we should be able to assume that you know where the coffee shop is. I suppose at the very least we should be able to assume that you believe that you know where the coffee shop is. The guy gave advice on backing up - he passed along someone else's advice, and said he it was essential advice. The relevant switch for your analogy would be asking him to be able to describe the code in rsync or dd or whatever. Nobody is doing that. They're simply pointing out that he didn't practice what he preached (with various degrees of unfortunate serves-him-right schadenfreude, but never mind that for the moment).
Answering a question implies a claim of authority. Offering advice on the internet (unsolicited) is the equivalent of building a freaking billboard with directions to the coffee shop.
http://74.125.93.132/search?q=cache:2HHNAk2SB6EJ:www.codingh...
I learned it the hard way.
It should be. It might even be in some of the plans. But most of the time it doesn't happen.
I have some backups and I'll try to get it up and running ASAP!"
Handling a failing disk is the job of a sysadmin, not a programmer.
Sometimes I'm extremely shocked at how cavalier professionals are at maintaining your data and I've worked with plenty.