how exactly does this happen?

florida by way of ABC news arizona

WESLEY CHAPEL, FL — A school resource officer’s gun accidentally discharged in the cafeteria at Weightman Middle School in Wesley Chapel on Tuesday afternoon, according to the Pasco County Sheriff’s Office.

Deputies say the SRO was in the cafeteria, leaning against the wall when his holstered, duty-issued firearm accidentally discharged into the wall behind him.

The gun fired directly into the wall and no students were in danger, according to the Sheriff’s Office. There were no injuries to any students, the staff or the School Resource Officer.

Supervisors have started investigating the incident and there will be a full administrative investigation into the matter.

as they have only started investigating no one has any idea whether it was ‘accidental’ or not