I do not know, just an idea, I'd check to see if there was any power going to the starter, maybe it is toast and shorting. Maybe there is a poor cable to battery terminal, loose connection, corroded cable terminal. Poor ground as mentioned. Any codes set?
Where did the AAA man make ground to the chassis, did he use the battery or another ground source like he is supposed to? If he did that may point to your problem, a bad ground.
I had a similar problem once, I had forgot to tighten the terminal clamp nut, suddenly, no start and no power anywhere.