Updated at 3:04 p.m. ET: The mystery man has been identified as a medical safety coordinator with Phoenix Air, the U.S. transportation company that has provided air ambulance services for several Ebola patients.

Dallas nurse Amber Vinson was transferred to Atlanta's Emory University Hospital Wednesday for ongoing treatment after being diagnosed with Ebola. She was helped from an ambulance onto a waiting plane by four medical workers in the now-familiar white hazmat suits, but there was one other person on the tarmac.

According to CBS 11 News in Dallas, questions about who the man wearing plain clothes and carrying a clipboard might be poured in.

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"On social media, and on the CBS 11 News phone lines, the biggest question became -- who was the guy not wearing protective hazmat gear?" said CBS Dallas.

Later Thursday, the mystery man, who boarded the plane after all the others and reemerged on the tarmac in Atlanta, was identified as a medical safety coordinator with Phoenix Air, the U.S. transportation company that has provided air ambulance services for several Ebola patients.

A company executive told CBS News the safety coordinator doesn't wear gear so he can act as the team's eyes and ears on the tarmac. They're trained to keep a safe distance from patients. Phoenix Air says it has transported 11 Ebola patients and no crew members have contracted the virus.

Contacted by CBS Dallas, a CDC official said earlier that it appeared the man had maintained a safe distance from Vinson while working on the tarmacs at both ends.

The CDC official stressed to CBS Dallas that only the workers in protective clothing were coming into direct contact with Vinson, and that the man didn't appear to breach any of the protocols put in place for the handling of patients with the highly infectious disease.

Still, the incident prompted questions.

CLARIFICATION: In his "CBS This Morning" report on Thursday, Dr. Jon LaPook commented on video from Dallas that showed a man dressed in civilian clothes while two workers in hazmat clothing helped Ebola patient Amber Vinson, also in hazmat gear, on to a plane. Here is an update:

"The video of nurse Amber Vinson boarding the plane to transport her to Emory shows a man with a clipboard on the tarmac. He was not wearing protective gear, raising the question of whether proper protocol was followed. However, today I spoke to the man with the clipboard. He is a physician and he was following protocol. He is a medical safety coordinator and his purpose is to be the eyes and ears on the ramp to make sure things are being done correctly. The protective gear worn by the other two members of his team impedes their peripheral vision, so the man with the clipboard actually had the best "big picture" view. The company, Phoenix Air, has transported eleven patients with Ebola over the past two months and no healthcare worker on its team has become infected - evidence that when protocol is properly followed, healthcare workers can be protected from being infected with the Ebola virus."