Burn time may have been longer as the fireball appeared to drop below my horizon as I was on the back side of a hill with respect to the fireball.
P.S. Fireballs are sooooo cool. The only other time I have seen one was a very dramatic one when I was in Worcester, Mass. back in the early nineties ('91 or '92 maybe?) around this same time (holidays) driving home late (around midnight) from some holiday event/gathering. That one was fragmenting dropping off baby fireballs as it went. Burn time (per my observation) was about two seconds.
