Um... didn't really leave that out, but if you want to repeat that part, I'm ok with that.
"There was threatening weather in the area so some cars stayed out on the track deciding not to pit in case it started raining/or lightning strikes occured.... and decided to ride it out until the the green next time by signal was given by Nascar. When that signal was given, then leader Kurt Busch and others pulled down pit lane, with Justin Haley, William Byron and others choosing to stay on the track. Before the cars were able to come around to get the green, there was another lightning strike, so the cars came back down pit road and were held there."
On the subject of clearing the stands/delaying an event for lightning for minimum of 30 minutes, I've seen it used at professional baseball games and at concerts, but don't remember it being an official policy until just recently. It's probably a good idea for safety reasons, and my guess, it's probably something that the insurance companies that insure the tracks are now insisting on, and I'm hoping that it was communicated to all the competitors/raceteams so nobody thinks they're making up the rules as they go.
I did hear Kurt Busch on the in car say (when after pulling down pit road with what appeared to be one to go to green, and then officials deciding to not go back to green due to "new" lightning) "They took one one away from me in 2016(?)" which sounded at that moment like he thought the move to not go back to green was Nascar's way of taking another win away from him. Not sure if even the biggest of Kurt Busch fans out there will believe that one, but there's always a few who like a good conspiracy story.
I've got no problem with the way the race ended as long as all raceteams, before the start of the race, were aware of the mandatory lightning strike within 8 miles resulting in a minimum 30 minuted delay policy.