Le dimanche 4 septembre 2016 16:56:29 UTC+2, a écritÂ*:
"They modified the canopy opening side for continuity after the glider was seen flying left to right in virtually every shot (except where a chase plane crossed from one side to the other)"

A reasonable assumption Bruce, but not quite. They were contractually obliged to shoot René Russo from her "good side", flipping the canopy to make it happen.

There are also interesting stories behind the producers wanting to cut the wings off the Duo to get the camera dolly closer, a replica that was made in the space of days and some amazing flying that never made it into the final cut.

Source: Tom Knauff, the pilot responsible

I heard another version still: it would have been to emulate the original movie with Steve McQueen, where the canopy opened to the right instead of the standard (for the 1-23) left...