"Correct you if you are wrong?" Well, OK. The tenant posted that the landlord's son was in the apartment "looking at a leak." It was a leak that went undetected by the tenant and went without repair by the landlord's son as he only "looked" at it. Then he left the place wide open if it was not indeed the landlord snooping. The whole action by the landlord and the maintenance man son was just plain stupid.
I was doing a double check on the procedure we would of used. Our procedure would of been different. First, if it was an emergency we would of tried to call and maybe email while on the way. Second, worst senario we would of checked out the leak, somehow tried to stop the damage. Very likely we might have to come back with drywall to repair damages after the leak. If there truely was a leak though and the maintenance man did not have the tenants number then it is the property owners right to stop the downstairs floors from being ruined.
Leaving the place wide open was very careless.
Also in the OP's senario something would of been torn up in their bathroom in order to see the pipes. mmhm
I am not saying the landlord was right. I don't know if we have the whole story either.