Must have landed short/heavy so as to cause the brakes to overheat. Happens quite often, however, those aircraft are supposed to go to another location well away from others. Fire Dept. is supposed to be there on standby for just such an incident to prevent it from damaging or destroying an aircraft.
In this instance, it sounds like a complete fustercluck because the crew most likely ignored or were "unaware" of what they'd done and neglected to inform maintenance of what they had done. And yes, aircrew are trained on what type of event may cause an overheat and are to notify maintenance personnel so a check can be done with an IR sensor just in case and then redirect the aircraft as required.
Either way, looks like a C17 has just become a cann bird.