My six year old DS isn't always cooperative during therapy sessions but he doesn't get violent or act out, he just acts goofy/silly and does the opposite of what the person says. I can see how a therapist might get frustrated and try to force a kid, or punish them, and it can spiral out of control.
DS's speech therapist at the school actually locked a child in kindergarten in a timeout room or closet, the kid freaked out and was yelling "I can't breathe!" because he was having an asthma attack. The ST thought he was faking it and walked away. The child had to be rescued by another teacher, and taken to the school nurse for a nebulizer treatment.
