That depends on the state of a persons metabolism at the time. You may have come out of ketosis and gone back in. You may not have come out of ketosis at all.
Either way, it doesn't make any difference to how much fat you've lost/not lost. That's down to the calories.
The main advantage of ketosis whilst on Cambridge is the reduced hunger/cravings, and you don't really need a stick to decide whether you have them or not.
Remember though that the calories will have some impact. Probably not a great amount, but there's always a consequence of extra calories. It's the psychological side that's the biggest killer. "Oooh, had one before and still lost weight/still stayed in ketosis...so I can do it again, and again" etc. That's the diet killer.