Is C.G. of wing itself in line with hang point (hang glider)? Where is c.g. of hang glider wing,at hang point ,in front or behind hang point?
Is control bar &quot;neutral&quot; when glider is at rest and there is no wind or flip backward or forward?
At 0:45 control bar  lay at seat,slightly &quot;nose heavy,&quot; so  this  wing c.g. is somewhere in front hang point(but to me seems very close to hang point,bar is almost neutral)

                
            
here is wing c.g.  excatly at hang point
The centre of gravity must imperatively be located between the nose and the quarter of the mean aerodynamic chord. The quarter of the mean aerodynamic chord is the point where applies the resultant of the forces and moments aerodynamic. One finds of it the definition theoretical low.
If the centre of gravity is placed behind the quarter of the average aerodynamic cord, the wing is unstable and completely impilotable... If the centre of gravity is too ahead, it is hardly less serious, the wing &quot; marsouine &quot; by carrying out oscillations around the axis of the pitching, oscillations which can, at worst if the control surfaces are not sufisament dimensioned to be able to increase the moment to pull up, not diminishing and leading to the crash..
Check out http://aeropic.free.fr/pages/modelisme/theorie/theorieenglish.htm#:~:text=The%20centre%20of%20gravity%20must,of%20the%20mean%20aerodynamic%20chord.