Okay, so the service rep said it indeed was the window regulator that was causing my issue on the rear passenger side window. Interesting if the above bulletin covers only the front passenger side window.
What's worse is that he said the part has to come from Germany and it'll take 7-14 days.
So, I'll put up the car and then he'll call me when the part is back in. Sigh.
At least the trip wasn't a total lost - they did fix a fuel gauge issue that I had where one of the sensors were bad. That part comes in tomorrow.
As a side note, they did give me a 2012 528i as a loaner and I hadn't driven a 5 series since my dad's 528e like 20 years ago. I didn't realize how much I would miss satellite radio as this doesn't have it. But it did have a bootleg Adele CD in it. HAHAHA (but there's no crying in BMWs!)