Dr$.$ Smith had an oral agreement with Dr$.$ Jones to take Dr$.$ Smith's $"$on call" patients while Smith was on vacation. The oral agreement included a compensation provision that Smith would receive $30$ percent of any fees collected by Jones and would see the patients in Dr$.$ Jones' office. While Smith was on vacation, Jones saw BillyBob, a patient of Dr$.$ Smith. Dr$.$ Jones misdiagnosed BillyBob's problem, and he died. BillyBob's heirs sued both Dr$.$ Smith and Dr$.$ Jones, claiming at the time they were partners. Dr$.$ Smith defended that he is not liable for BillyBob's death. Which of the following statements is most correct?