The paraglider is not the same machine as a parachute, as you have
noticed. It has a higher aspect ratio (width to length ratio, for you
non-pilots) which gives it a greater glide ratio. Greater glide ratio
equates to greater instability in a paraglider. Instablility, in this
case, is the tendency of the paraglider to collapse under, for example,
the varying the front-to-back air pressures of thermal activity.

Paragliders are not designed to take terminal deployment -- that is, a
full-fall deployment. They are made of lighter materials in the sail
and lines. They can come apart at terminal velocities.

Paragliders have more cells to inflate and are not nearly as stable as
parachutes.
Once inflated, parachutes tend to stay inflated while paragliders do
not. Any small end-cell deflation in a paraglider can cause a
spiraling down condition. Unless the pilot is on the ball and shifts
pressures to the deflated side the spiral develops to a point where it
is unrecoverable. This happens in matter of seconds.

Finally, the shape and condition of the paraglider is critical. This
shape changes over time as the material wears and the lines stretch or
the fabric becomes more porous. The flight characteristics of a worn
paraglider can make it positively dangerous regardless of the
conditions.

Antonio