He said using a knife for suicide is "hardcore" and not the usual method.
According to local press reports, Walker had been treated by mental health authorities when he told friends he was thinking of killing himself.
Coffee house owner Ealy said that so far about 10 of the audience members had already availed themselves of the counseling services, provided as part of the Central Oregon Critical Incident Stress Management Team.
Mark Taylor, deputy chief of training and safety for the Bend fire department, said they had teamed up with the hospital's mental health behavioral unit to help witnesses and their families to understand what they might expect.
"They are all together in one room and they have shared that horrible event," Taylor said. "These people now share a horrible bond, whether they like it or not. It's not unlike war. ... We warned people that if they have alcohol issues or a drug dependence, this is a great trigger and it could get worse."
The session was just a "foot in the door for people," and witnesses were given information on where to seek more help, Taylor said.
"We are not trying to make people whole again in one session," he said. "A lot of people just need to put a voice to the trauma and what they are going through."