How to refresh old table item values based on new inserted item


I am new to Vaadin and am having some problem with values of Item in the Table.
I have a form which has a boolean field and a user field and for a particular user that field can only be true once. That check and modification happens in our backend(service) code which is not related to Vaadin in anyway.
Anyways, the problem I am facing is that in the table if the user has item that has that boolean set to true and for the same user if we save one more item which has the boolean true then we have two items which have true for that field. Which is not in sync with the backend. To have it sync I have to reload the page and after the reload the UI displays correctly i.e. the first item has the false boolean and the second has true
One naive implementation that comes to my mind is that I could check on every new item that if that field is already true for that user somewhere in the table. If yes I could changes that to false. But for this I might have to iterate through the table.
Is it a good idea. Can I do this is some other better way ?
Please do ask if you find some unclarity

(P.S : The vaadin version I am using is 7.1.15)