Assuming that you are both looking at the same record in the same database this should not be possible. So the question becomes are you infact looking at the same record in the same database? Is it possible that the client is somehow looking at a copy of the database, say a local copy on the local computer or a one that is on a file share on the server instead of the actual served file? If he is somehow looking at copy in the Server's backup folder it is possible that he is seeing a record updated 2 weeks ago on the same layout you are using, while you are opeing the live copy on the server and seeing the live file/record with the current timestamp.
Best of luck tracking this down.
I have a client on server FM server 12 on a Mac. It seems that is a problem with records being updating. When I log on I see the record as updated today, but another user see the record last updates 2 weeks ago. I added text to the layout to make sure we were on the same layout and record and the same database.
I had a similar experience with a client. The time span wasn't weeks. We were both logged in and viewing the same layout. He was not seeing changes that I was making. This went on for about ten minutes. It wasn't until he closed the database and re-opened it that the changes were visible to him. Then we had the same experience again. It was necessary for him to close the file to see changes. However, the data I was touching was in a related table, so I think that he was seeing cached data that did not appear to need updating.
Is it possible that external file references could be matching an older version of the data?
Have you checked out the Clients tab in console and the logs?
That should at least tell you which databases were accessed.