What they're calling "confabulation" is making up a deontological rule, such as "everyone has a right not to be drafted for anything except defense", or something like that, to explain/justify the shudder.

If you don't make a deontological rule and insist that it have no exceptions, in any particular case you will be tempted to find an excuse why it doesn't apply. As Eliezer said in his post The Ends Don't Justify the Means:

And so we have the bizarre-seeming rule: "For the good of the tribe, do not cheat to seize power even when it would provide a net benefit to the tribe."

Indeed it may be wiser to phrase it this way: If you just say, "when it seems like it would provide a net benefit to the tribe", then you get people who say, "But it doesn't just seem that way - it would provide a net benefit to the tribe if I were in charge."