'kudu ksck --verbose' sometimes omits existing tablets from the output

While running 'kudu ksck --verbose' periodically during a test scenario where tablet servers were killed one by one (spaced by some 15-20 min intervals) and then starting them all back, at some point 'kudu ksck --verbose' stopped outputting information on one tablet, but then that information returned back.

That behavior is quite unexpected and should be corrected.  I'll to add more details once I have good reproduction scenario.