In all likelihood, the seat of the pants will tell you to do the wrong thing here. After years of teaching acro and unusual attitudes, my general impression echoes what Markkal said: the vast majority of pilots will not build the mental orientation required in the split second available to them and will immediately do the action that comes naturally in all panic-type situations: pull.
Part of the problem is that, as he said, the plane is already trimmed for +1G and even if the pilot does nothing, will quickly begin to nosedive.
The other part of the problem is that through many years and thousands of hours spent within 25 degrees of bank and 15 degrees of pitch, brains build up an incorrect model of how the controls work (on top of simplistic theory taught on the ground): that the ailerons are for turning the plane left and right, and that the elevator is for going up and down. That set of notions works most of the time in standard transport profiles, but breaks down when you get outside those confines. But if that's the model in the brain, when pilot finds himself upside down with the nose plummeting, you can't really blame him when he naturally calls up the only reaction that has always yielded him the "go up" result within that model: to actuate the "go up" control and pull back on the yoke.
The correct model is centered around the lift vector, and how the controls manipulate it. Fighter pilots talk in these terms a lot, as do good aerobatic instructors. (Mediocre ones just list off the steps for performing maneuvers.) The ailerons are for aiming the lift vector (which always points out the roof of the airplane), and the elevator controls its magnitude, or strength. These 2 functions are paramount for airplane control, for the airplane just goes where the lift vector points. A brain inculcated with this model (via careful consideration of the physics on the ground, and hopefully many hours of aerobatic practice in the air) will do the right thing: first, aim the lift vector at the sky, and only then increase its strength with the elevator to pull out.