Inside scoop from someone that works there:

Son bypasses metal detector because of his condition, and was offered the same specialized screening they're used to. (5-second hand test)

Machine alarms on test, and the mom and all their bags had to get extra screening. (nothing extra is done to the son)

Mom gets pissed off that she has to get pat down, and refuses to cooperate. Yells and screams that this isn't what happens at other airports, etc.

Mom's behavior gets the son upset, and he starts crying. Tells his mom to stop.

TSA calls for backup as tantrum continues, in the form of managers, police, etc.

Mom eventually complies and vows revenge.