Same issue here.
Work and home machine.
It was an issue on Windows 7(x64) and it's still an issue on Windows 8(x64).
Even if the background app service is disabled.
And chrome is definetly offline...it just leaves some of the history in there.
I have no idea how you are unable to reproduce this since I myself have never actually seen this part of the cleanup work. EVER.
At first i thought it my be the fact that we're logged into google...but heh the "share history" option is disabled so that can't be it.