An38 said...
...I would not worry. 0.01 is a very very low reading. We have had many cases here where the methodology of testing has changed at the laboratory or the machine just was not calibrated correctly. A reading of 0.01 is normally a cause for celebration. ...
Actually, there seem to have be a slew of recent cases, some quite notable. IMO, labs across the system are not consistent enough in their machines, standards and calibration methods to be considered totally reliable at ultra-sensitive levels. This could be as simple as the person operating the machine and doing the calibration moved on to a different job.
Not anything to be concerned about
.