Engine Noise problems of the 2011 Mazda MAZDA3

I stopped at a stop sign and my car started accelerating as if the accelerator was fully depressed. My foot was squarely on the brake at the time but I was being pulled slowly forward on to a busy roadway. I am an experienced driver and was able to turn the car sharply to the right along the shoulder to avoid oncoming traffic. I shifted into park, and then shut the engine off. My foot placement was no where near the accelerator, and there were no other obstructions (I. E. Carpets). When I restarted the car the engine sounded normal. As an engineer, I am fairly certain that what ever happened was electronic in nature, not a mechanical obstruction or sticking linkage (I did not touch the gas pedal when I restarted). Prior to this incident I had been driving slow though a business park at 10 to 15 miles and hour for a couple of minutes, I was at a doctor appointment. I have not seen this issue before or since. Mazda has examined the car and did not see anything. I like the car, but I thought it was important to get this potentially dangerous flaw on record.