Who cares how big the shed is? Leach confined him to a relatively small, dark area by himself and forced him to stand up for several hours. It's certainly not torture, but it's obviously just weird.
I don't care if the kid is a pantywaist and a slacker; it's beyond stupid this year to punish a kid whom doctors have identified as being legitimately concussed. Especially when you already have a crappy relationship with your bosses to begin with. I certainly don't think this by itself ought to be a firing offense, but if Leach does get the axe, it's going to be tough to feel very sorry for him. He walked up on the gallows and handed the AD the noose himself.