Interesting cars, aren't they? Every one of them seems to have its own set of a few quirks.
Mine does actually release the rear pretty well with the front already off using the hoist, but then I don't lift it more than just enough to get the rear just off the car. I set the handle to release position before starting to raise the top, and when I start to raise the top it tilts only slightly to the rear before the rear starts to rise (thanks to my hoist sling being carefully balanced). If the rear pin hangs up, it does so with the rear edge of the top perhaps a half-inch or so off the car; the front will be maybe 3-4 inches off at most. At that point, I can work the release a few times while gently supporting the top and get it to release.
The backup maneuvers that can be used have filled several threads on other boards, but basically reduce to these three:
1) Rotate the top 90 degrees til the pin releases--NOT recommended, but it's been done;
2) Use a bent wire/screwdriver/whatever to move the latch hook toward the passenger side of the car to get it to release; and
3) Get a narrow-nose visegrip on the pin and rotate it 90 degrees, counterclockwise as viewed from below (passenger's side of pin moves toward back of car).
I did have mine hang up early on, and I just now realized why number 2 above wouldn't work for me. The hook has to move toward the PASSENGER side of the car, and I spent an hour trying to move it the wrong way. But then, I'd never have invented number 3.....