A buddy of mine who used to live in Alaska is the Biologist who runs the Julia Butler Hansen Whitetail Refuge.
Is his name Paul?
Helped with the relocation project back in 2014.
Here is a shot of a blacktail and a whitetail along the Columbia River. You can see the difference in the color of their coats .
Yes blacktails will run with their tails up showing a white flag but no where close to a whitetails flag in highth and width.
The last picture of the 2 deer is exactly what I saw, one had some black on it’s tail the other had absolutely no black, just pretty much same color of the body. If anyone in the Olympia area is ever out by Summit lake in the morning or early evening drive through on the 1st exit heading west and take a look. See deer pretty much every day in the mornings and evenings.