Yeah, that sounds like a broken process. The story is the last possible moment of decision making before the developers go and develop something. Obviously it

Yeah, that sounds like a broken process. The story is the last possible moment of decision making before the developers go and develop something. Obviously it may need further refinement at a later date once you have learned something. But, by definition, you now know -everything that can be known before development starts-, because development is about to start. As such, anything, -anything- that remains unspecified, is, again, by definition, undefined. It may be worth explaining that if failure conditions remain undefined, then you will ignore them for convenience, because whatever you decide to do will almost assuredly be wrong. If the product owners want -any- say in what it does in the event of something going wrong, and don't want it to be a surprise, and require even more work, then now is the time to say something.