I had it happen to me in Beaver, UT in my car. It was a fuel stop on the east side of the highway with a tire shop attached. A guy came by and told me one of my rear tires was going flat. He said there was free air on the side of the building. When I got there to check things out, there was a guy waiting to check my pressure for me. He said it was very low. I started getting a weird vibe. There was no alert in the instrument panel. He said he would fill it. Then, he just went a few secs and said - oh, he overfilled it. That was too fast to be overfilled. Then he said he could get me a good deal on a tire and got me a price. I was not feeling right so I went on my way. There was nothing wrong with that tire.