I can't believe he offered to drive it without a windscreen.
Thankfully this windscreen is Pilkington and actually slightly different to the first one they fitted which was also the same brand. That one you could feel a curve on the top of the windscreen where the sensor area is when wiping it, whereas this one is nice and flat. Perhaps that's why the rain sensor on it bubbled so soon, I don't know.
Anyway, the dispatch centre called me just now, what they will do is send someone out tomorrow to look and make note of exactly the trim and clips required and inspect the bodged job the last guy did. So I won't have a new trim tomorrow but if they get it wrong now it will be beyond comedy.
The technician that phoned me today left me a voicemail too saying he'd left a complaint with his manager and dispatch team as it makes people like him look bad, which is fair enough as I can understand not all of the guys doing the work do it poorly..
Edit*
I'm sure the clips weren't broken to start with because the glue was still wet and rubbed all over my fingers. I couldn't even wash it out for days... And the fact that I'd have noticed it not fitting properly before anyway.