"there were a couple of stray fireworks fired over the course of the next hour"

From my understanding (and I could be wrong), once professional fireworks are set-up and armed and they start to be fired-off, they can't be "unset-up"/unarmed. They must be fired. They can't just pack them up for next time. If they fail to fire during a show, the technician(s) must troubleshoot and still fire them off. Sounds like these techs had more trouble than some with the amount of "appendices" they had to the main show.