I think the factory just sealed between the gasket and the body. The b bodies only have a pinchweld for the gasket to wrap around on the top and sides, unlike most car that use four sides. The bottom of the gasket just sits in a depression in the cowl. This area for sure needs sealant. Sounds like the glass shop tried the easy fix first by unzipping the gasket and sealing between the windshield and gasket.