I am an AA employee, but nothing I post is sanctioned/supported by AA.

One thing that comes to mind is that the random checks were announced and the pax went on board dropped his jacket off and then went back out for further screening. Well, to me that would be suspicious if he left items on board the airplane, before doing the extra "random" screening. I assume that is the reason he was called off board the airplane, after reading the accounts from the agents law firm.

If anyone else boarded a flight, before going through a random screening, and then left items aboard the airplane I think some eyebrows would and should be raised. It is possible that an individual could have picked up the LEO form already filled out and scratched out the flight number. There were some legitimate concerns, but the addition of the Arabic background kicked it all into overdrive.

Without knowing what exactly went on between the CA and the agent after being rescruitinized, I can't say if the CA made an error or not. I personnally would not care for an angry man with a gun to be seated next to me, but the question then is was he mad before or after the CA "questioned" his credentials.