Leaks around windshield gasket

What a mess. That professional installer didn't know ambient temp minimum is 70 degrees ? The gasket was supposed to be pushed all the onto the fence, then the glass put in the gasket. Keep in mind that if a percentage of you metal fence has rusted away you would have issues requiring more sealant between the glass and gasket. Anyway... if that was mine I'd just start over.
Good luck with it.