Well, after re-running the calibration and profile generation this morning, everything looks fine (see below). In all the years I've been using SpectraView I've never seen anything like this. I can only conclude that something occurred during the previous calibration that caused some kind of corruption...perhaps a bad read from the i1Display Pro device or an issue writing the updated LUTs to the monitor. Caused by some intensive activity on the system CPU or disk?? I dunno.
Anyway it just highlights that you really need to examine the calibration results before blindly assuming that it worked OK. Other than showing you the bad calibration data, SpectraView doesn't really tell you that an error occurred.
Dave