The law does not require professionals to give guarantee and warranty with respect to the end results of their services. I never give any assurance or guarantee.

No doctor can give 100% guarantee about the outcome of the treatment or surgery. The only assurance which a doctor can give or can be understood to have given by implication is that he is well equipped with requisite skills in the specific field he is practicing in and while undertaking the performance of the task entrusted to him he would be exercising his skill with reasonable competence.

(39) To exhibit reasonable skill: The degree of skill a doctor undertakes is the average degree of skill possessed by his professional brethren of the same standing as himself. The best form of treatment may differ when different choices are available. There is an implied contract between the doctor and patient where the patient is told, in effect, “Medicine is not an exact science. I shall use my experience and best judgment and you take the risk that I may be wrong. I guarantee nothing.”