WOW! Lucky guy (both of you).
I've never had a hangfire that was more than two seconds or so myself. But you can bet that gun with a load in it would have been pointed at the sky or the ground so long as it was in my hands.
It could have been a hangfire. Or it could be the he had the lock c0cked and pulled the trigger to unc0ck it. A flintlock will fire on occasion with no powder in the pan.