I was riding home today on the shoulder where there is some gravel and some small rocks/bits of asphalt. I was going pretty fast and keeping up with traffic. I rolled over some of the gravel when I heard and felt the back tire deflating. I stopped to repair it and found two TINY holes on the tube 3-4 millimeters apart. The holes were so small that I only found them by holding the tire up to my ear to listen for the hiss. At first I thought this it was a pinch flat, but I'm questioning that now because the holes were both on one side of the tube, not on the top and bottom as one would expect.
My tires are 700x28. The combined weight of me and the bike is about 260 pounds, so I had the tires inflated to 100 psi as per this chart I found on the forums. As a precaution, I increased the pressure in the back tire to 110 psi but kept the front at 100.
Do you think this was a pinch flat or something else? By the way the rim tape is hard plastic.