What you had on that day is called DUCTING. I'm a ham radio operator and have made many contacts like this.
Not uncommon and I myself have spoken to a fellow ham in New Zealand a few years ago on a handheld 2meter radio. This ducting can be caused by many things. Mostly though its the warm weather that cuses it. Think of the air as if it has 3 layers. Sometimes the inner layer gets warmed up and the outer 2 stay cooler. Radio signals travel throught the warmer layer and eventually come back to earth,this distance can be short or long depending on how long the ducting is. Antennas are a whole new ball game and what most people forget is that it might work better in some cases that in others. A GOOD earth to the vehicle is a must! You can check the earth connection out using a multimeter and should have less than 0.7ohms for a good earth. More that that and it will work but not that well. And to answer you last bit yes a good chance he may have heard you had you pushed the PTT.