It's not the stalling that would worry me. It's the fact that when you tried to restart there was nothing, not even any cranking.
The only thing that could cause this would be bad ignition switch, wiring issue, a shorted sensor that is causing a problem with the PCM or some other control module.

Keep running it and see what happens. That's about all you can do. Let us know if it rears it's ugly head again.