ITunes took Utube-type movie files and duplicated the audio only and added it to Music in iTunes

Question

I have about 8,000 short video clips in my iTunes library and about 9,000 songs.  When setting up iTunes Match, i noticed some ineligible files were titled as if they were video clips (ie 'Drunk guy slaps wife at church').  I checked for that same file name under Movies in iTunes, and there it was--in MPEG4 format...it played normally, video and sound.
I went back to the audio only file in Music of iTunes to find that it was an ACC audio file with an 'm4a' format.  The video fiile is 13MB, the audio only 3MB.
I've found about 20 files that have been duplicated this way. 
QUESTION:  I have never extracted the audio only portion of these video files, and I don't go around encoding or changing formats of my videos.  How in the world did the audio of a video file show up in the Music section of my iTunes as a duplicate to an original file found in my Movies section of iTunes?!
If you have any ideas, I'd apprecate an explanation to this mystery...I'm starting to believe in supernatural powers.
Thanks!

Answer 1

Launch the Console application in any of the following ways:
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.
☞ Open LaunchPad. Click Utilities, then Console in the icon grid.
The title of the Console window should be All Messages. If it isn't, select
          SYSTEM LOG QUERIES ▹ All Messages
from the log list on the left. If you don't see that list, select
          View ▹ Show Log List
from the menu bar at the top of the screen.Click the Clear Display icon in the toolbar. Then try the action that you're having trouble with again. Select any messages that appear in the Console window. Copy them to the Clipboard by pressing the key combination command-C. Paste into a reply to this message by pressing command-V.
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