No. It was NOT a short. In most cases it is a loose, intermittenr, or high resistance connection that causes a fire - not a short.
In order for this to happen there MUST be a load of some sort on the circuit. A normal breaker will not respond to an "arc fault" of this type, and nor will a CFCI - an "arc fault detector" breaker is designed to trip under those conditions. Not sure how effective they are in real life - or if they are more likely to false trigger.