Of course any file can become corrupt. The disk can go bad, another program can overwrite it, Windows could do something funky with it, there might be a bug in the TD.
As far as that file goes, it's unlikely (but not impossible) the TD corrupted it, for 2 reasons: (1) the format is very simple, and thus it's unlikely a bug is in there due to "complexity"; and (2) the format has not changed in any meaningful way in over 5 years. If there was a bug that caused it to become corrupted, I would have heard about it .. a lot.
If you make a change to a player's nickname, firstname, or lastname, or change any season data, or change any league data or league membership, that entire file is rewritten. So in that sense, most changes made to the database cause that file to be "rebuilt".
If you have a player that you keep having to add to the database, or that you cannot seem to delete from the database, honestly I would look more closely to make sure you aren't simply adding/deleting the player from the tournament.