nose up, flyable airspeed, sink rate none-the-less = loss of lift due to pulling G’s at high angle of attack = high speed stall. Happened to a Thunderbird pilot during an airshow at Mountain Home AFB in 2003. He successfully ejected about one second before impact. Here is a link:
http://www.bing.com/search?q=Thunderbird+Crash+Mountain+Home+Idaho&FORM=R5FD6
Stall, separation of smooth airflow over the wing, loss of lift, meaning no lift generated because of disrupted airflow. The Hunter and the T-Bird did not stall. They were flying. An aircraft that is stalled is not flying.
Nice short explanation here: http://www.allstar.fiu.edu/aero/flight55.htm
And a very short vid (by a friend of mine): https://www.youtube.com/watch?v=5wIq75_BzOQ
Cheers.