My experience has been that, at any given time, there may be 20-100 alarms indicating in a nuclear power plant control room. Realistically, they can't all be immediately treated as valid. The reactor operator must judge the validity of each alarm and decide what response is appropriate. If no judgement was needed, the alarm input could as well be hardwired to produce the desired response. I suspect that similar conditions prevail in Bell's remote monitoring location.
Fire alarms are notorious for spurious indication.
Hot days, impaired ventilation, dust, etc. can erroneously activate various types of fire alarms. Another risk of automatic alarms is created by the inappropriate choice of technology. The VAX and Sun computers for my group at LLNL are located in two machine rooms. Each machine room is equipped with smoke detectors which are checked on a regular basis. The machine rooms are often unmanned.