Best practice for detecting errors with DS1820 thermometer sensors

What do you consider very close and how would you know that very close reading is in fact an error and not a correct value anyway?
If you actually are measuring in the range of 0.05°C I'd guess you wouldn't care if it was an erronous 0.05 or an actual reading of 0.05°C plus/minus a few10th of degrees (considering the accuracy of the sensor anyway ;-))

From the datasheet

How about that?