a bit of follow-up:
took the car to the dealer. the service guy looked at it, understood the problem immediately and noted that the fool who had done this had used sealant rather than adhesive and observed that if he had used adhesive it might have worked. He wasn't prepared to guess whether this fix had been done by the dealer or the factory, but we did find some abrasions on the shotgun side trim which suggests that there might have been some trauma to the windshield installation after the car left the factory. Alas, we'll never know.
He agreed that the only way this could be fixed by them - Koons in Baltimore, a class act except they charge for coffee in the service waiting lounge - was the right way. Hooray!
So he ordered up new trim strips and the possibly broken underlying attach-strip and said he'd call me when they came in - not back-ordered either.