Rounding error in Moving Time in splits?

When I do a Run activity with auto lap every 250 meter, I have noticed that my Moving Time for each split is always slightly shorter than the time of the split, even though I have been moving all the time.

This evening I noticed a pattern:

• If the fractional seconds of the split time is above 0.7 seconds, the moving time will almost always be the split time rounded down to full seconds.
  
• If the fractional seconds of the split time is 0.7 seconds or lower, the moving time will almost always be the split time rounded down to full seconds and subtracted by 1 second.
  

I have a suspicion that this is because the GPS logs once every full second, but start and end of splits are interpolated between two full seconds. And then when calculating moving time, the algorithm takes the first and the last full second within the recorded split and subtract them from each other.

If it was just my moving time which was wrong, I could live with it. But it annoys me to see two different paces - Average pace and average moving pace - where the only difference is probably a rounding error.