Sailplanes are adopting forward hinged canopies as a safety feature.
Any canopy opening system can open inadvertently if not properly
latched but the forward hinge system will open less violently than
other systems.

Regardless of the hinge system, an open canopy is not likely to render
an aircraft unflyable. The first priority is to FLY THE AIRCRAFT and
deal with the canopy on the ground after a safe landing.

Long experience has shown that the biggest hazard of an open canopy in
flight is the pilot trying to close the canopy and not flying the
aircraft while he's doing it. There's a history of glider accidents
with this scenario. Glider pilots are taught to assume an open canopy
is trashed, put it out of their mind and fly the glider as an open
cockpit aircraft.

Bill is correct. The biggest hazard of an unlatch/open canopy is trying to close it. I can make this statement as a "voice of experience."
http://www.soaridaho.com/Schreder/HP-16/nocan.htm

I only had about 30 hours in glider when this incident occurred. If I my glider had a forward hinged canopy the result of an unlatched canopy would have been a bit of noise caused by the canopy not being properly sealed.

One of these days I am going to have to replace the canopy on my current homebuilt sailplane. When the time arrives a I will install forward hinged canopy.

Wayne
http://tinyurl.com/N990-6F