I had an interesting chat with the service manager at a large VW dealership about this kind of thing. Although I had an idea what might go on, his comments clarified it.
He outlined that every time a car is brought in for warranty work, it's down to the dealer to a) use their discretion to work out whether it's a warranty item and then b) pay for the parts and labour up front themselves. Then, at at a specified interval - sometimes as long as a year he said - the "man from VW" would visit them and agree what they would reimburse the dealer for.
Apparently anything up to 25% of the work would be rejected, leaving the dealer to stump up for it. I am not defending the dealer in this case, but if that's how manufacturers routinely run things, it seems delaers might have to try and get what they can
No less annoying for us as the customer though
