I caught just a few minutes of it while I was getting ready for work tonight. I did notice when they squared off with the British at Lexington that one of the patriots was lined up ready to fire, but his frizzen was forward.
Didn't see the show but I've done that very thing by accident with my flinter at reenactments. Only happens in rapid (sort of) fire. Common usage at reenactments when loading from wrapped paper cartridges is to prime the pan first and then pour the rest of the powder down the barrel (there would be a ball in that cartridge in the real thing).
Authentic maybe, but means you're loading over a primed pan, not a good thing. I always pour the main charge with the pan open and then prime last from a priming flask before closing the frizzen.
Maybe once or twice out of hundreds I've forgotten and brought the arm to bear with the frizzen open over the empty pan.
On a related note, in "The Patriot" some of the militia turn their heads away from the pan when firing, this is because in that movie they mixed powdered magnesium in with the priming charge to give it a brighter flash for the camera
Birdwatcher