"We believe that we are not at fault"
Fine. I will see you in court.
I will seek 473 quintillion dollars in punitive damages. That's eight teen zeros if your vocabulary is lacking and I will liquidate your company and your client company and use your desk as a tool bench for car repair.
Juries love David v Goliath stories to adjudicate. But, my desire would be clear to a jurist, liquidate the companies involved that created the massive injury and properly punish them.
Because, their assertion is that they're not responsible for their own contractors contract ignoring errors and that's equal to, "It's not my fault that my gun went off while I was raping your daughter and now she is dead, it's the gun manufacturor's fault for it functioning properly".
At least, by the time I and my legal team are done telling and framing it.