This happened in south Jersey i believe. With no warning. At the time of the lightning strike. The man was under a tree that got hit first. People living next door to the golf course say ' It was perfectly sunny out with no storm near by at the time of lightning and thunder"
With all of the "popcorn" storms popping up out of nowhere this is likely to become more frequent. All you need is a mass of unstable air (warm/humid). If you are watching the weather radar this go from amorphous green blobs to yellow to angry red in real time (like 15 minutes). That cell will rapidly dissipate and a new one forms nearby. It looks like popcorn popping in a pot on the stove. These cells are moving quickly, 25-35 mph ground speed. If the cloud base is two to three miles above the local terrain a lightening strike is possible at a distance of two to three miles away from that base.
We had some of these move through in the last few days. If you are under one of these cells it's pretty intense as it passes through but you need to be careful even if the main action is several miles away. It's really weird to hear thunder booming all around you but the sun is shining and the sky directly above is clear.
I used to keep a browser tab on my computer at work open to the regional weather radar in the summer months to monitor for such storms. Our main building had two wings. The newer research wing was almost completely glass "curtain walls" which had the potential of becoming a giant Cuisinart in the event of a direct hit from a microburst or funnel cloud/tornado. If the sirens went off everyone was to take shelter in the basement of the old wing.
BTW, the ground field prior to a strike is pretty intense. If you can feel the hairs on your arms starting to rise and nearby siding starting to vibrate/sing you need to get away from anything "tall" and try to crouch down (not lie down) to present as small/short a target as possible. If you lie down a near miss could still pass through you.