This will probably crash:

vec_set(temp,my.z);

"my.z" is not a vector, so you will copy garbage. "my.x" is a vector that included x,y,z.

vec_to_angle(my.roll, normal);

This also crashes, for same reason. "my.pan" is a vector that includes pan, tilt, roll, but my.roll is not a vector.

You want probably to do something like this:

c_trace(my.x,vector(my.x,my.y,my.z-5), IGNORE_ME);
vec_to_angle(my.pan,normal);