Thou shalt not cast aspersions on Mother Nature's color of green, I sayeth verily unto thee.
On a slightly less biblical note, your observation that the battery cell voltages' variation is within reasonable limits amounts to an assurance that...
Besides Palomar Mountain State Park (which is not where the guy was flying from), there are numerous desert state parks that also do not allow drones to be flown from within them, including Anza Borrego, Salton Sea, etc.
If his videos are monetized he has to let the park service know his drone flight is for a commercial purpose and detail that to them. Recreational flights are fine unless posted. Part 107 flights are another thing.