There was a youtube documentary I saw at least 5 years ago (before the max disasters), who had a hit piece on boeing. They duped them into letting them film in the (North|South) Carolina plant (787 I believe), until they started asking pointed questions about safety and were asked to leave. They interviewed (off-site) one of the hourly manufacturing employees who attested to a bunch of careless practices. This was right about the time one of the Middle Eastern airlines said they only wanted 787's from Seattle, not the Carolina plant.
Even though their documentary proved prescient with the Max problem, I still don't think they were able to really connect anything. IIRC most of the documentary focused on mechanical issues, leaving pliers/plastic junk inside the airframe, whereas the root-cause turned out to be a systems engineering: MCAS and allowing cost-saving on one AOA sensor.
I would try to find it, but given all the recent press, I highly doubt I could. It may not have been Youtube, it could have been Al-Jazeera or Vice, etc. But if you pick the most popular flying vehicle and then start a doomer prophecy, of course there will eventually be something that makes it sound like you were right.