Radiator valve, Steam

Client called me, wanted me to inspect damage from a radiator that had been removed, and the valve left in closed position, not removed and capped, valve leaked and filled condo up with steam when boiler came in middle of the day, I referred her to insurance company, My question is, I now in my younger days when working with HVAC contractors doing re-hab He/ We alwas capped off live steam lines, your thoughts please