SEVERAL VERY ABRUPT PULL-UPS, SEVERAL VERY ABRUPT LEVEL-OFFS
AT VERY LOW ALTITUDE, AND SEVERAL HAMMERHEAD TYPE TURNS. THE LAST MANEUVER,
WHICH TERMINATED WITH THE ACCIDENT, WAS A STEEP PULLUP AND CLIMB FOLLOWED BY
A HAMMERHEAD TURN AND A DELAYED PULLOUT AT THE BOTTOM WHICH RESULTED IN
IMPACT WITH THE TERRAIN.

Look at that again. "Several abrupt pull-ups", and "delayed
pullout at the bottom." The guy was not familiar with accelerated
stalls, or, in other words, the effect of G loading on stall speed. He
pulled hard enough to stall the thing and it wouldn't level off.
I see some guys showing off after takeoff, buzzing low along
the runway then pulling up hard. You read accident reports again and
again that quote witnesses saying that "the airplane pulled up and
rolled right and dived into the ground." Same goes for guys that buzz
their friends: pull up and roll over into the ground. One wing often
stalls a little earlier than the other, especially if the airplane
isn't coordinated, and an unexpected snap roll is the result.
And their friends say, "I don't understand. He was such a good
pilot! Must have been something wrong with the airplane..."

Dan