Well...doesn't that just confirm that Casey was lying all along and deliberately leading everyone (perhaps even her attorneys) to believe that Caylee had ever been a missing child?
Casey was found guilty of lying to LE. One of her lies was that her daughter had been kidnapped by a babysitter, and she went as far as to give that babysitter a name. Then three years later Casey, by way of her attorney at trial, admitted Caylee had died the first day and was never missing.
IMO, it will not matter if her attorneys try to claim that Casey waited for three years to tell them that Caylee was dead and had never been missing. These lawsuits are about how Casey's lies led to huge expenditures for public agencies and ruined reputations of private citizens who she pointed at as being culpable. Her defense proves she lied to investigators and to the public. It proves she deliberately attempted to send the investigation off course. These suits are against Casey--not her attorney, so for these particular actions, when Casey told Baez that Caylee was never missing is not relevant. That would become relevant only if someone decides to sue Baez, or if the state bar goes after him.
The problem I still see though is you are trying to prove that Casey knew her daughter was dead when the searches went on and legally nothing has been proven that she did. Nobody legally has been held accountable for Caylee's death, when they knew she was dead, etc. You bring up the OS but the problem there is the OS is/was not evidence. Casey didn't admit anything because she didn't testify to the fact in a court of law that her baby drowned.
Now, if she would of got on the stand and actually testified to a drowning, then you got something.