Jayse Anspach was also on the plane, and described the incident in a series of tweets, saying, "A couple air port security men forcefully pulled the doctor out of his chair and to the floor of the aisle. In so doing, the doctor's face was slammed against an arm rest, causing serious bleeding from his mouth. It looked like he was knocked out, because he went limp and quiet and they dragged him out of the plane like a rag doll."
It's unclear what exactly happened after the man was removed, but a video posted by another passenger several minutes later shows the clearly distressed man was allowed back on the plane with blood visible on his face. He repeatedly says, "I have to go home."