The only time you will see someone else's card is when you log into more than one NFS account from the same database. The temple cards are stored within the RootsMagic database. Once the card has been completed, FamilySearch removes it from the system. RootsMagic keeps a local copy of the cards that you've loaded so you can track cards as they are completed.

When you login into the same database with a different NFS ID, you will receive a warning asking if you really want to load the cards. You will need to check the boxes next to to the other person's temple cards and then click "Delete".  It will now load your temple cards.  

The temple cards for each NFS login on that database will now show.  Cards assigned to "Me" could reflect either user. You will need to assign the cards a helper (your name)  to keep track of which NFS login they belong to.