Glad I started this thread - it's been educational and fun! Now to relate a little story of the first wedding I ever photographed.
I used my Retina Reflex with Tri-X and bulb flash. I was very nervous as the bride was an old family friend. When I got home that night and was putting my equipment away, I realized the flash setting was on 'X', not 'M', in other words, it was set for electronic flash, not bulbs. I couldn't sleep that night.
The next day I took one of the last rolls, which was just some general shots as the reception was winding down, and really souped it! Amazingly, I had usable negatives - not great, but usable. Guess the duration of the bulbs helped. I souped the rest of the film, made some acceptable prints, and presented the couple with the albums when they returned from their honeymoon. They were very happy with the results.
Fast forward 40 years. Spouses have passed away, and I marry the old family friend. She has become a good photographer herself. I tell her what happened with her wedding photos of so long ago. We have a great laugh over that from time to time! Isn't life interesting?