You'll need to describe that in more detail.
What you describe would seem impossible in FileMaker so there must be some details missing from what you described.
Are each of you opening the database by using Open Remote from the File menu?
Exactly how are you hosting the database ? With FileMaker Pro? FileMaker Server? If using Pro, Is FileMaker Pro installed on the computer where the file is located and used to host this file?
Was the user in Browse Mode or Find mode when typing in this text? (There are many ways to search for data in a FileMaker database and only some require the user to be in Find mode when entering their search criteria.)
Where you by any chance using any kind of remote desktop access application to access the database?