Bug in enclosure urls for exchange pieces

[kookster]

Looks like if a file ends in .MP2 instead of .mp2 (I am somewhat guessing), then the derivative broadcast mp3 file in exchange is saved differently

For this story:
https://beta.prx.org/stories/447924

It gets the story info from cms, including this enclosre link:
https://cms.prx.org/pub/bd44fca49da2f8ced3bcdd1e1c298f17/0/web/audio_file/3875759/broadcast/AA400A.mp3

Which forwards to this s3 filehttps://s3.amazonaws.com/production.mediajoint.prx.org/public/audio_files/3875759/AA400A_broadcast.mp3

But, the file was generated on the exchange at this location:
https://s3.amazonaws.com/production.mediajoint.prx.org/public/audio_files/3875759/AA400A.MP2_broadcast.mp3

My guess is there is a bug in the exchange on handling that capitalized file extension, and it didn't get removed as it should.
Not sure how to fix that now without making a bunch of files not work on the exchange, maybe have to look at the created date from before the bug gets fixed?