Calculating absolute roll/pitch/yaw angle of falling objects
First, a few assumptions: I'm going to assume you have 3-axis accelerometer and 3-axis gyroscopic sensor (angular velocity sensor) and that all six of those channels are logged at sufficient resolution for the duration of the jump.  Further, I'm assuming that it is sufficient to reconstruct the motion after the jump and that we don't necessarily need to calculate anything during the jump.

First, the freefall portion of the jump should be easy to detect with the accelerometer because it would be the portion during which all three accelerometer axes report zero (or very nearly zero).  Orienting the values relative to earth can be done by a combination of inferring "up" from the point at which the person is at rest and on the ground after the jump (because it's opposite the direction of the acceleration due to gravity) and inferring horizontal orientation (e.g. "North") from the compass.

Second, the angular velocity (gyroscopic) sensor only senses just that -- angular velocity.  So to infer a relative position you would need to multiply by time.  To be concrete, if the angular velocity were 360 degrees per second (3600 rpm), after 0.25 seconds the position will have been changed by 360 * 0.25 = 90 degrees.  To back that into an absolute position (relative to some arbitrary starting position), you might need to infer that the person is standing upright just before freefall begins and when angular velocity in all three axes are zero.