Analytics servers do not differentiate timestamps if they are have the same second. For example, hit 1 has time stamp 01:01:01.3 and hit 2 has time stamp 01:01:01.5. Analytics will treat both the timestamps as 01:01:01. Now, the order of the hits will be decided on which hit arrives first on the servers. So, if hit B reached the servers first, the order of the hit will be Hit B > hit A.In order to prevent this, it is advised that the hits should have at least one second's different. Therefore, h...

I'm not familiar, but perhaps it's related to this data latency issue from yesterday? https://status.adobe.com/

Was the user removed from Analytics is that what this scenario is? You can disable the user by simply setting the range on the user account for the date that they are able to login from to the previous days time. So what that would do is not allow the user to get into the account at all from the Cloud that would be one way. And then you should be still able to use the segments created by that user for sure. Will that work? Or is there something further you are looking to do?