Originally Posted by DFC
The pitching direction depends on the position of the engine and the thrust line and drag line.
DFC is, of course, quite correct. However increased slipstream over a bottom mounted elevator (i.e. not a T-tail) is likely to increase elevator authority. Therefore pushing forward on the control column with an increased slipstream will tend to lower the nose (relative to the pilot) on most aircraft.
Of course this also ignores the effect of the CG around which all the moments will rotate. If the CG is too far aft, then no amount of elevator authority will lower the nose, which is probably why an aft CG is cited as the most common reason for entering an inadvertant flat spin.
Any spin can be defined as autorotation in any three axes. Whether it is "flat" or not depends only upon the relationship between Roll and Yaw, since the attitude of the aircraft is immaterial. The trick to getting out of a flat spin is to ensure rate of roll >= to rate of yaw. You can do what you like with pitch! Unless this leads to an increase in the rate of roll, your spin is still flat.
For my money, I could live with a pitch up just as easily as a pitch down upon closing the throttle. A pitch down is likely to enter a normal spin. A pitch up is likely to enter an inverted spin. Both are equally likely to promote roll, and therefore permit a standard spin recovery.