Been watching Dugway for years and yes, I caught that. The restriction window was odd - not the usual pattern you see for scheduled tests. Those tend to run predictable hours, this one shifted twice in 48 hours which I dont think I've seen before.
What's your source for tracking them? I use FlightAware and a secondary tool but I'm wondering if anyone cross-referenced with ADS-B Exchange during the same window to see if anything was squawking that shouldn't have been.
The thing that keeps nagging at me is the geographic boundary on the restriction. Did anyone actually plot the coordinates properly? Because if my mapping is right it extended well beyond the proving ground perimeter which is unusual.