I suspect the blame for that one is all on the SGC people. I'm pretty sure there wasn't a self-destruct before Zelenka set one up back at the end of Season 1. And it's almost certainly McKay that rigged it up so it could be activated by the operating system without requiring activation by 2 or more of the command staff—real smart move on the part of someone who's been burned by Wraith computer viruses on more than one occasion.