Subject to K.S.A. 60-416, and except for presumptions which are conclusive or irrefutable under the rules of law from which they arise, (a) if the facts from which the presumption is derived have any probative value as evidence of the existence of the presumed fact, the presumption continues to exist and the burden of establishing the nonexistence of the presumed fact is upon the party against whom the presumption operates; (b) if the facts from which the presumption arises have no probative value as evidence of the presumed fact, the presumption does not exist when evidence is introduced which would support a finding of the nonexistence of the presumed fact, and the fact which would otherwise be presumed shall be determined from the evidence exactly as if no presumption was or had ever been involved.
K.S.A. 60-414