I bet anything they wouldn't come after you for damages. The lawyer fees alone would be worth the claim. And if they did I would drag the case out as long as possible. I bet you could keep that out of a court room for 1-3 years if you played your cards right. What possible damage you you possibly be liable for? I would sign it and tell them to sue you when you find another job. You should dare them to sue you. I bet they are all bark and no bite. Even if you were found liable what money could you possibly have being a poor CFI? Wost case scenario is they would file a judgment and I would take many years for them to get their $2 claim against you.