I am not sure if it is a bug or not ...
I am also syncing my Contacts using Traveler. I created a list of my contacts by myself.
I also have a sister with the same lastname ... If I like to search for the lastname of my sister I get all(!) contacts since the search seems also to search in the CreatedBy field. Since I created the contacts and I have the same lastname as my sister always all contacts are found.
Also there is pain if searching for the firstname! Also having contacts which have the same firstname as I have (my firstname is Harald). If I like to search for all Haralds in my contacts I also always getting all contacts ...