At the risk of invoking Godwin, this is exactly how Hitler used to behave in IRC.
Sorry, I had to say that, it's my condition... anyway..
In last nights situation I think it would have been much better to suggest to wildfire_cs that they email a copy of /etc/fstab to either iDunno or quinophex, for them to then make the required changes and email back the changed file. wildfire_cs could then save the original and replace it with the edited version and bingo problem solved.
With the greatest amount of respect in the world, that would have involved all of the same file operations as doing it via IRC.
Both options involve backing up the file, then up to a sudo/root login, then overwriting the file.
The only significant difference I can see between the handholding approach, and the "via email" approach, is that the second approach involves the user doing those file operations unattended, sudo/root login unattended, and making crucial decisions, as sudo/root, unattended.
I have no wish to gainsay anyone here, still - if the options are "logging in as sudo/root unattended to apply a pre-edited file" vs. "having several people who understand what you're doing helping you in realtime and checking your output", then doesn't the preferable path almost seem to be a matter of objective fact?
Just goes to show how we all have different ways of thinking, and how we shouldn't assume that somebody else's decisions aren't the result of sound critical thought, just because they don't agree with our own.
Of course, when you raise matters of liability, you raise the question of whether people should refuse to help others through fear of things like litigation. Making a personal decision on that one, doesn't mean you're blind to the possible consequences. It may be an ethical decision.
On the whole, it's completely heartening to see you've such an ethical attitude to technical support.
Hope the job interview goes well, and that you got back to sleep quickly.
Be lucky.