Check all battery & electrical power connections
Check ignition leads to coil
Check ignition switch
Load test battery
Check voltage at battery during a fast idle….should be greater than 13,7

 

Carb - Na, because it happened before the tune.
Battery - Going to say no to that because he was trying to start it for 30 minutes worth and shows voltage on reserve. Or say he's running total loss and the battery comes back up to start it...Don't believe it, but as of now without the static volte number, not it.
Crank sensor - Common type is the thermodynamics of it heating up and 'lights out,' cools and lights backup.

My closes guess from info explaining 'lights out.'

 

I’m no genius, but this this post by YZR is what just happened to be. And like the OP, I tried to understand under what conditions the failure occurred. By the time I could coast to the roadside, the bike would fire right back up without sounding sluggish. And indeed after setting myself on fire after the second carb removal and going through everything fuel delivery wise, I noticed the mfg date on my RatedX battery was ‘17. Crap…nearly 7 years on that battery. Anyway, point is, the stalling while running and starting ok etc fooled me. New battery and haven’t a hiccup in over 400 miles. Slowly regaining faith in the bike to not strand be.