Those who are surprised by Jerry's statement either haven't been keeping up with the team's happenings or is in denial of them. Both Jerry and Stephen have been praising their staff both lately and for many years now. It's especially so, in matters pertaining to Jason Garrett.
It might take games similar to those happening during the era of Wade Phillips before JG and his cohorts are cut. As long as the team plays hard for him, he'll likely be safe.
In stark contrast to that, though, there are no guarantees that this will be so indefinitely. Players have a way of becoming lax and unproductive whenever the wins aren't forthcoming any longer.