You clicked on both action and MUSIC. That better explains the results. Data is pulled from TMDB and can't be changed except if you polished data for each movie manually. And there are 300,000+ movies.
Yes, it seems to fall more on the side of false positives than false negatives. While this is a safe bet, it is also less useful, since the main use case I can think for this is to help me pick up some movies from the plethora of available movies that exist in the world to maybe look for in Netflix etc. I mean, "Take This Waltz" (2012) is not what I'm after if I'm looking for films from Japan. Mildly annoying.