It can happen, and as other stated bad luck...

This year on the maiden ride of my new build, I got a flat 3km from my house, it too was a cut in the tire that was about 8-9mm, in a new Deda Giro tire... I could have swore I did not ride over anything. I booted it, patched it, road home and purchased new tires.

Thats the nature of riding. The other day a club ride ran over something that tore the sidewall of his tire. He was running GatorSkins, it was just bad luck....