YOU are the Fire Alarm Specialist
I have heard this from fire marshals since I started in the industry, and I have come to understand that it is true. You are the specialist. We are the fire alarm specialists.
The fire marshal is a person that reviews many aspects of construction. We work just one small portion of the many things he inspects and reviews. Why does this matter? We are the people who install the first notice of danger and threat of death. Our trade is what people quietly count on. If we do a poor job, people die, possessions get destroyed. The rules and laws or standards and codes we follow are specifically put in place to make sure a fire does as little damage as possible . To make sure everyone is warned and safe. So when someone points out codes and standards to you, they are not showing you "the most severe installation scenario from the meanest fire marshal" they are showing you how you should have been trained from the beginning. And if you respond with "well no fire marshal has ever said anything about that", remember, you're the specialist. Show him what life safety is. It's not just a job. What you do in this industry determines if you get to save all of the lives, some of the lives, or none of the lives.
Learn the Rules.
If the fire marshal finds one thing wrong with your work, then it is you who is not doing their due diligence. It is you that is not applying their follow-through and making sure your work is done correctly. It is you that is showing poor workmanship. If he has to know what kind of concrete burns the fastest, if steal melts faster than wood burns (it does), if the room you installed in will hold 50 or 75 people and what codes are involved with locks, width of hallways and maximum amount of stairs before a landing then you should by all sense of reasoning know your simple trade which is just a tiny portion of his work. He should not find anything wrong. Unless you are a fly-by-night company just doing a few jobs to get out and not care about code (ugg) you should understand everything you need to do.
In my early years in the fire alarm industry, I asked a fire marshal "Whats the secret to "Should and Shall thing" and this is what he said to me: "Best way I can say this is, How long you been in the industry? Almost two years? After two years, you should be able to look things up for yourself and tell me what shall be installed". So you should not be asking the fire marshal anything about what shall be installed.
The Fire Marshal is Right
He was right when he says "I don't know, you're the specialist, you tell me".. You should be able to design and install a safe fire alarm system easily to code and not get rejected by plan review or building inspection. EVER.
The fire marshal should not be your biggest worry. The fire marshal is the last person to look out for you in this industry. If you get failed by the fire marshal and you fix what they noted, be thankful. Be thankful it isn't the insurance company rolling up to hold you accountable for a poor installation that doesn't meet the requirements you must follow. That would end in fines, loss of license, loss of a career. It could land you in jail or prison.