I had this happen to me on a solution I created with Filemaker Pro 11, turns out the database had been corrupted and eventually I began finding more and more of these question mark records. I was able to solve it by running the recovery and the process gave me access to the data that I then transferred to a good known copy of the file.
I don't recommend that you do a full up recovery for this as that could make unintended changes to your file.
Just rebuild your field indexes and this "phantom record" should disappear.
Launch FileMaker without opening the file
Select Recover from the File Menu and select your file as the file to open. (File Cannot be hosted from server when you do this.)
Select advanced recover options and select the following options:
Copy FileBlocks As Is
Rebuild Indexes [Now]
This produces a copy of the file where the only change made was to rebuild the indexes.