>>84
Yes, we can, lots of ways. First off, if God would smite your friend specifically, then given the relatively low number of people who get hit by lightning bolts compared to the number of people who do things generally considered to be morally wrong, he'd have had a pretty good reason to smite your friend. You'd be able to take a survey over a large number of people who get hit by lightning every year and see a pattern in the actions they've been doing to see what pisses off God.
Second, we know what causes lightning; friction in air molecules causes electrostatic buildup in clouds. Pretty soon we'll be getting better and better technologically at detecting where lightning strikes will occur based on things like air density. We'd be able to detect this deity by seeing a sudden impossible shift in air conditions causing a lightning strike to hit a specific person (or simply averaged over many people, we'd see stranger behavior in air conditions when people are hit compared to inanimate objects).
Third, we know how people are made vulnerable to lightning. It's not logical for God to only smite people who go golfing on stormy days, or who stand around in open fields. People usually stay indoors during a storm, and especially in big cities, there's virtually always another target for lightning to strike. I'd have a hard time calling it a deity if it can be thwarted so easily; call me when lightning bolts start shooting through windows to hit child molesters.