It seems like one difficulty is in knowing what expertise is important? Assumedly the contractors thought they had expertise, but were lacking. The firefighters assumedly thought they had expertise, but we're lacking. What expertise do I think I have, but am actually lacking?
Yeah, that's difficult. The only answer I've found is experience. Gaining experience for yourself is painful because it's slow, and part of the experience is consequences of your mistakes: in fields like fire-fighting (or rock climbing, which I love) your mistakes can literally kill you. So hopefully you learn form other people's experience and mistakes as much as possible.