I'm a little surprised it had the air flow to purge the water lines, but apparently it did so, to your satisfaction. I guess there must have been sufficient capacity in the pipes and such to store sufficient air for a faucet, and then it can recover and you could repeat for the other taps.
How high a pressure do you use in your tires? A lot of these little inflator gizmos really bog down or even poop out when trying to get a tire up to, say, 80 psi or more...but not everybody needs that high of a pressure for their rigs.
At any rate, it sounds like a very handy gizmo for you, and I'm glad it has worked out so well.