Back glass install frustration

The other day I roped in my back glass. It went in very smoothly with a friend pushing gently on the outside as I pulled the rope around the inside. Except for the right lower corner.

I finally persuaded the rope around that sharp angle, but the glass does not feel fully seated there. I can flex it up and down about 1/8" to 3/16", compared to the other corner and everywhere else where it feels rock-solid. I can't see very well into the corner but can only assume that the gasket lip didn't pop over the pinch weld way down at the tip.

Any suggestions? I have no experience with this kind of work. Should I just keep trying to pick it (I have a ball-end pick tool on the way) or take the glass/gasket assembly out and start over? Worrying about breaking the glass with too much handling, or tearing the gasket... thanks.