Hi Alex,
Regardless of any merit to a case, anyone these days can file a lawsuit against anyone for any reason. While you have done what you were hired to do, you can still be sued regardless of any lack of merit. Even if you win, you still have legal fees, inconvenience and time wasted. I think you should provide your findings to those who hired you and let them base their decision on whether or not the developers are meeting the terms of the contract. An hour or two consulting with an attorney would be money well spent as well.
Good luck!
Mark McCasland
Midlothian, TX USA