When Gordon put an open flame under the sprinkler head, all of the sprinklers in the room began to spray. This would never happen. The only sprinkler heads that will open up during a fire are those close enough to the source of heat to cause either a solder bulb to melt or a glass tube with a temperature sensitive fluid inside to break. This focuses the water pressure only to the area where the fire is actually burning.
When Gordon and Bullock go to the Merton gang hideout to try and find Jonathan Crane they aren't wearing gas masks. Yet they know how dangerous the chemical agent Crane makes is so it's strange they didn't take the proper precautions.