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Whether it takes 1 second, 10 seconds, ten minutes, or an hour to equalize the pressure with the outside atmosphere is neither here nor there

Beg to differ. From beginning of depressurization to vehicle away would be less than maybe 1/8 of a second. No let's say I have 12 miles of tube. At mile marker one I place one baloon, at mile marker two I place two baloons, and so on, I pop all the balloons at once. The pressure readings are going to differ for some time after. No matter what scale you use this is the way it works. Been fun, but I gotta go coach soccer, I'll see what you have when I get back.

Ah, I have five more minutes. In you model, how does the front of the wave "know" what the final equalized pressure will be. In fact, as air enters the tunnel it creates a bit of a vacuum compared to the surrounding area. The air molecules bounce around, vice proceed on a direct path, thus, some of that leading wave is always turning back. If the pressure behind them isn't as great, as it was at the beginning, a forgone conclusion, then not as many bounce back in the initial direction. As time progresses this leads to a diminishing pressure. This effect is constant trough out the air mass, and thus you have the effect of slowing increasing pressure in the path of propagation.
Despite the subject, this isn't really rocket science, but rather freshman (in HS) chemistry.

At mile marker one I place one baloon, at mile marker two I place two baloons, and so on, I pop all the balloons at once. The pressure readings are going to differ for some time after. No matter what scale you use this is the way it works.

We're talking about just a bit more air than that, and hence, "some time after" is going to be quite a bit shorter than with your balloons. After you open your door, there is going to be some point where the pressure at the bottom of the tube is still zero - no air has reached the bottom yet - but is something else, some non-zero pressure, higher up the tube.

Now, if you happen to be standing in the middle of the tube, there is going to be a point where the pressure around you increases from zero to something, and rather rapidly too. The farther away from the mouth of the tube you're standing, the longer you're going to have to wait for that to happen, because the air has to travel down at the tunnel to get to you. But it will happen, because that air is coming, whether you paid attention to Boyle's law or not.