The points had to have been opening slightly or the car would not have run. The spark occurs when they open, breaking the circuit and collapsing the electrical field in the coil causing a spark discharge.
It is not a good idea to have them closed for extended periods with the key on, as it can pit the points. If you didn't specifically use distributor cam lube, the plastic tang will quickly wear off. You can always use a matchbook cover to gauge the point gap out in the field. That will be close enough to get you home, where you can then use a dwell gauge to set the proper gap.
Jeez, i'm dating myself aren't I?
1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 4.10's
1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3800 stall lock-up converter and 4.30's (closest thing to an automatic 5 speed going)
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