Call me a pants s**tter but I have no desire to get jammed up by NYs criminal justice system. When I visit NYC (my daughter goes to school there) I don't even bring a pocket knife.
To groundscaper's comment regarding the TSA in MCO suppose you were connecting through JFK or LGA and TSA demanded you open your luggage to do an inspection. Luggage was checked but they know you have firearms because you declared them when you began your journey. You have to open the bag and unlock the cases in front of an officer. Bingo! You are now "in possession" of your firearms and subject to arrest.
This happened to me years ago under completely different circumstances. I was bringing some instant ice tea to my wife's aunt in France. I had two containers of tea in my checked luggage. TSA screened the bags, thought they looked suspicious, and I was paged, had to go to an office and open the luggage and show them the tea. Imagine the same scenario with firearms.
Does TSA call people mid transit to open bags?
I have never seen this with domestic flights.
Your example is an international flight. Are you saying you checked your bags in Boston, then had a layover in NY (you didn't touch your bags) and TSA called you to open your bags?