Are phone's gps refresh-rates even fast enough to provide an accurate reading?
Also, radar/laser guns are supposed to be calibrated on a schedule. Maybe it was off as well compounding the issue. I believe one of my friends got out of a ticket (because he loves fighting in court for some reason) and he was able to pull the records of the radar/laser gun the cop used when he got clocked and it was past it's scheduled calibration and he got out of it. He was totally speeding but