It will take losing 3 or more of the last 7 with Romo playing for them to even consider firing Garrett. Or a situation where it's evident that he's lost the team,a lot of grumbling from within the lockeroom,etc. The same could be said if they had any other owner. So it's not just a Jones thing. No team is going to fire a coach coming off a 12-4 season,when you can point to injuries being such a big factor.
Let's face it. If they go on to win 5 or 6 out of the next 7 it would be clearly obvious that had Romo played. We'd have ended up being 11-5 or better. So it would be hard to make a reasonable case for firing Garrett. If they lose 3 or more. Then firing Garrett would be a fair argument.
Stephen seems to be more in charge now days. And he seems to be pretty cool headed and logical about things when making decisions. So I'm sure he'll let the rest of the season play out before deciding to hire or fire anyone. Which is exactly what he should do.