Should a 6-year-old Have Been Punished for Taking Lego-sized Gun to School?

WCVB News in Massachusetts reports that a local kindergartner was given detention and faces possible suspension from the bus after taking a Lego-sized gun to school recently. The gun, reported to be no bigger than a quarter, was seen by another student, who alerted the driver. The boy's mother told the news channel that her son was given detention, had to write a letter of apology to the driver and even faces possible suspension from the bus.

The school sent home a letter to parents assuring them that no real gun was on the bus and that there was never any danger, according to the news report. The driver is reported to have said that it caused a disturbance and the children were traumatized.

The mother of the 6-year-old reportedly believes it was an over reaction.

What do you think? Correct reaction to the situation by the school, or an over reaction as the mother believes?