An autistic teenager was suspended from school after showing off a picture of a bomb he had drawn.
Officials sent 13-year-old Rhett Parnham home so they could decide whether he was a threat.
But his mum Amy was left stunned by the school's response and said her son was incapable of making any explosives.
The saga unfolded at Hillcrest Middle School in Greenville, South Carolina, when Rhett drew a picture of a cartoon bomb from his favourite video game, Bomber Man.
Mrs Parham claimed school administrators said they knew Rhett wasn't a threat but they were worried about how his actions would be perceived by other parents.
"I'm angry. I'm upset and I'm incredulous, that a child could come in and bring a drawing and that's somehow perceived as a threat - especially someone with special needs who really doesn't filter information the same way that typical children do," she said.
"They were worried about their perception. Perception is reality, and parents might think you have a bomb or [might be] violent."
A statement from Greenville County Schools said: "This investigation began when threatening comments were made, resulting in the responsible removal of the student from the school to ensure everyone's safety while the incident and intent were assessed."
South Carolina's education association director Janet Stein added that the school principal had acted in the best interests of the students.
"Principals are in a very difficult spot with this ... if something had happened, the district would have been accountable for that."
At a two-hour hearing the school decided Rhett's actions had been influenced by his autism and agreed to revoke the suspension.