Another little joy about engine fire warnings, spurious ones tend to bring the light straight on, real ones it glows dimly and gets brighter. I used to fly one aircraft where the lights were on when you switched on the batteries and went out when you started the engines! (that was a very smoky old 355) IIRC the S61 system was a wire full of a really poisonous substance (cyanide?) which regularly gave false warnings if someone had been careless on the A check, the 332 had bi-metalic sensors which became weak with age, as for the 76 I can't remember, I had a few spurious warnings over the years until the day, on a go round, when there was a nasty high speed vibration, followed by a humungous bang and no 1 stopped. the fire warning took some time to come on, but needed both bottles, by that time we were at VTOSS, climbing nicely away from some very tall platforms, towards MSA and had loads of time to sort the problem. The P2 was able to confirm the fire in his mirror and we both said afterwards how much like a drill it had been.
If the warning had not gone out after the second bottle we would have gone into the water, which would have been hard work as the go-round had been caused by low clouds, poor viz. If we had held the height at 50-100' to sort the problem we would have been flying towards a lot of much higher structures, with one pilot concentrating on low flying while the other did the drills without much confimation from PF.
There was a long discussion in the crew room about this at the time and one guy was very aggressive in his opinion that the engine shut down drills should have been done before anything else. A couple of months later he flew into the hill west ABZ while executing a perfect engine shutdown and not flying the beast, luckily for him the TRE could re-set the sim and send him off again.
SOPs are for the protection of all, but certainly with that company a captain was allowed to deviate from them if he believed his actions were were the safer route.