Privity is a requirement in almost all cases of legal malpractice.  One particular sticking point is the negligently created estate.  Who has the right to sue, if anyone?  Here is a Texas case which differentiates between the damaged estate [think: unnecessary tax, costs, loss of assets] and a disappointed will beneficiary.

In this case, the estate was able to sue its attorney, even thought testator was dead. The Texas case.