Looking at the history of one of these files I can see when it was added (directly, without merge) and a later edit.
There's a changeset in TFS which couldn't be clonned to git because it has merged changes of a branch that wasn't clonned. This changeset has some of the missing files, but they were on another project that doesn't exist anymore.
Anyway, as you can see in the capture, the file exists in TFS and it was added directly (not from a merge)
Is there any command to retrieve any file and its history (if it's possible) after making the clone?