According to an article published in the American Journal of Emergency Medicine – No.

In a study done using college students with no previous CPR training, students performed CPR on a mannequin first by phone instruction only, then later after taking a hands-only CPR course, and then 4 months after taking a full CPR AED course.

Participants relying on phone instruction only took longer to begin chest compressions and a few did not have their hands on the correct location on the chest. The article didn’t state it, but I do not know if stress, or lack of, was included in the study.

Participants performed more quickly and correctly after taking a course. Hands-on practice in a CPR AED course can improve bystander response.