True , the trim at the bottom of the windshield pulls out easily, but the glass may have been broken when it was re-installed! It's quite a coincidence ( or a real stretch of the imagination ) that the "stress crack" occurred at the same time that area of the vehicle was worked on. In my dealership, if prior defects/damage are noticed in an area that's about to be worked on, a shop foreman is notified immediately and it's noted on the repair order. This eliminates any problems later on. See if the repair order for your last visit has any such reference to the damaged glass. Lastly, it's not uncommon for the blower regulator as well as the motor to be replaced together. I've seen regulators fail with no warning many times on cars like yours shortly after motor replacement. Good luck