Most likely, the vast majority of the lightning did go through his ground rod. By the old saying about electricity taking the path of least resistance is only partially true; it takes every path it can find. You can see this in your motorhome right now. If you have more than 1 light bulb on, the electricity doesn't just go to the one with the least resistance, it will go to all of them that are on. Lightning act the same way. Lets say that a bolt of lightning is 2 million volts ( I just pulled that # out of my a$$), and his ground rod had a very good ground with only 2 ohms of resistance, but the lightning found another path to ground though your buddy's work bench that had 20 million ohms(made that up, too) also.
Ohms law tells us that the ground rod saw 1 million amps, and his work bench got .1 amps at 2 million volts or a total of 200,000 watts, which was enough to fry his electronics. The hope of ground Protection is that the majority of the electricity will flow through it and the amount of amperage through other paths will be low enough to not damage anything, but with a direct lightning strike, all bet are off.
