In California and many other states a statutory presumption of undue influence on the donor exists when somebody receives a gift and the receiver of the gift (donee) has either
a) drafted the document that effectuates the gift
b) transcribed such document
c) was a care custodian to the donor when the document was signed by the donor including the period 90 days before or after.
In addition, the presumption also applies to certain person related to or closely affiliated with the donee. For exact language and more detail see California Probate Code Section 21380.
This presumption may be overcome by appropriate evidence that there was no such undue influence or fraud. This can be accomplished by involving an independent lawyer (i.e., a lawyer who does not fall under the categories of persons listed above) who may issue a “Certificate of Independent Review” under Prob C §21384.
It is important to know for the parties engaging the independent attorney that certification does not mean that the attorney examined the transaction regarding any possible flaws, legal ramifications, tax consequences, etc., but only certifies that the transfer is “not the product of fraud or undue influence.” See also: Engaging a trust and estate lawyer – Defining the scope of representation