As an integrator, I can relate with this discussion, and particularly Rodney, Marty, and Timothy's thoughts above.
There's a manufacturer we've been dealing with for well over a decade. Their support in the past was outstanding, and we were well recognized (by them) as being able to support their systems on-site as well as any of their techs, often making extensive field repairs ourselves, with their blessing. We love their systems, so we've speced them (and continue to spec them) for almost all of our customers over they years, and on the whole, those customers have been very happy with the systems as well.
In particular, one major customer of ours has deployed over two dozen of these systems in the six years they've been with us, with plans to continue using them for future sites (including two currently under construction). However, some of the newer systems have been having some related peculiar issues, and manufacturer support has been spotty at best, generally blaming our installation of the systems or specific setup options that in some cases have been working flawlessly for 5+ years. Where in the past, they would work extensively with us to actually find resolutions to these problems that didn't involve massive overhauls of the installations, they've recently taken to simply saying, "Nope, not our problem, here's your machine back."
Fortunately for us, this customer is also very tech-savvy and we've kept him completely in the loop as to our attempts to support them, and the manufacturer's stonewalling and run-arounds. He sees and appreciates the lengths we go to, as well, and realizes that we're doing everything WE can (and sometimes more) to keep them running, while the manufacturer continues to shoot themselves in both proverbial feet.
The customer HAS made it clear himself to the manufacturer that he's not pleased with this, and WE'VE made it clear to them that the customer has requested we start looking into other platforms for their future sites - he loves the product, but we're all fed up with the continually declining support.
So in answer to Rodney and Marty, if the integrator is being up-front and they are having a LEGITIMATE issue with the manufacturer, then they should have no problem producing some sort of paper trail documenting that they're holding up their end of things. And ultimately, if they can't make the system work, they should have no issue either refuning the end user, or replacing the system with something that DOES work.