You could prove malicious intent which would be criminal, but typically employers don't hold any real liability as long as they fulfill the project contract. Minor disagreements on the final product are hard if not impossible to hammer out in the legal system. Otherwise, the originator of the work would have free work done forever after based on excuses. People generally find companies or independent contractors where they like their work, and stick with them, and move on from those they are not happy with.
For the middle layers, they take nothing but money out of your check. For the endpoint subcontractor that hires the actual worker, he would hold some responsibility to manage the project, but I wouldn't term that as liability in the sense that it's normally used- legally. As far as the responsibility to deliver according to requirements? That's actually nearly entirely on me. That's where the pressure ends up being.
I'm personally about 4 layers deep as far as separation from the originator of my project. 2 of those offer no actual value at all other than ill-gotten gains for themselves.
