I played my first game against someone using a saboteur the other day, and while the situation never arose I did have a question arise.

Let's say after using saboteur the opponent gets a crit revealed like "Damaged Sensory Array" (or any of the other crits that let you flip it over eventually). Then let's say a turn or two later they resolve it and flip it over. Can the saboteur then turn that same card over AGAIN? Or can they never turn the same card over twice?

Can the saboteur then turn that same card over AGAIN?

Yes.

Or can they never turn the same card over twice?

No such limit is mentioned anywhere.

Of all face-down cards on the target one is randomly choosen. That is all there is.

The card specifically tells you to choose a random card and flip it faceup. In this instruction you have the potential to choose a card that was a crit that the player has already resolved, even if it was resolved from a previous saboteur action.

The choice is a random one from the cards available.

I played my first game against someone using a saboteur the other day, and while the situation never arose I did have a question arise.

Let's say after using saboteur the opponent gets a crit revealed like "Damaged Sensory Array" (or any of the other crits that let you flip it over eventually). Then let's say a turn or two later they resolve it and flip it over. Can the saboteur then turn that same card over AGAIN? Or can they never turn the same card over twice?

Therein lies the power of the Saboteur. You can't pick which crit gets flipped, but quite a few of them are absolutely horrifying to get repeatedly.