A couple of years ago, an IP and an IUT were up doing an OCF/high spins syllabus flight (note: this is NOT the Wing 4 incident, so no privilege is attached). At the top of the MOA (25K? I can't remember) while trying to get the aircraft to go progressive without much luck, the IP told the IUT to recover. The aircraft refused. The IP took the controls and made another attempt. Nothing...just still spinning it's way down. I don't remember how many attempts he made (all IAW NATOPS), but he blew through the MOA floor in the process. At 10K, he "notified" the IUT, "hey, I'm going to try one more thing, but start to get ready back there." Yikes.
The IUT started cleaning up and getting ready but fortunately the IP got it to recover on the last try. I don't remember what they recovered at, but it wasn't much above the NATOPS hard deck of 5K. They decided they'd go ahead and knock it off for the day.
One of those times when the actual "Notify" was a legit step. Still gives me the willies thinking about it, though.