About 10 years ago my son was using a brokered ticket to Alaska. He was crab fishing and called and asked me to change his ticket home, because of weather he had been stuck at some port, could not reach the airline, and was leaving in the next few minutes to get back on the boat.

The airline immediately became suspicious and begain asking me questions about where he got the ticket etc. I said he was my adult son who had just got out of the Army and I assumed he had the ticket from an Army contact.
I was able to get his ticket changed, but they did question him closely at the airport. By that time he had talked to the broker and had some particulars.

I had used the broker two times for myself before that and always had the sellers particulars (aunt from Toledo) and had no problems.