Yep, I was surmising that at room temperatures and/or ambient air ... it's probably not designed for that.
So yes, with a helper we each immersed a probe in about an inch or so of water (careful not to touch the bottom of the pot) and watched the water boil. It's NOT true what they say, a watched pot CAN boil; it's about as exciting as watching grass grow however.
As the water got hot the readings got closer. They never touched on the same number until about 180 or so. Both held at 212 F, as expected, but the one side that always read higher did ping 214 before we ended the 'speriment.
So I'm no longer concerned.
Speaking of tests, I just also picked up an oven thermometer, the Taylor TruTemp from Target,
http://www.target.com/p/taylor-trutemp-oven-and-grill-thermometer/-/A-11010614#prodSlot=medium_1_1&tempterm=taylor+oven+thermometer and it was spot-on at 212 degrees F.