During my first 3 month with linux I tried to change settings from xorg and crashed my machine twice.
crashed twice for xorg configuration failure???
I DID crashed my knoppix machine several times but it doesn't have anything to do with X. All it does is managing display.
I assume that he is using unstable version or that the system crashed was caused by some other reason.
However, what he says is not necessarily wrong.:
If you failed to edit xorg.conf properly, X cannot work therefore you cannot even get the graphical login prompt (where you type username/password and enter). In such case, what you can do is to get the X work all right by reeditting the xorg.conf file WITHOUT MOUSE BUT ONLY KEYBOARD on the console. I mean:
"If you saw your graphical interface corrupt, you need to press ctrl-alt-f1 (choose one of f1-f6) to open virtual console. There you can prompted to enter username/password. Login as root and edit xorg.conf with 'vi /etc/X11/xorg.conf'. "
Like I always say, manpage will be a great help for you there.