It looks like you've identified an issue with the way this is reported ... the 'last login' is literally the last time they logged in by typing in their username and password, it's not resetting that time if you click the 'remember me' checkbox so you don't have to log in.
The algorithm for removing inactive owners actually uses the last time you accessed a page in that league, and both of these owners have been active.
I'll make a note that this needs to be fixed.