I may be stepping on my wee-wee here...

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This is a legitimate controversy, and not made up... and will be investigated by more qualified than me,.. but...
This is my area of expertise... (also, video, film, editing, foley, engineering, and effects)...
I have worked professionally as an audio engineer, in video and audio production for over a decade...
I know, light and sound recording... I have taught it,... in college and university... (so, I'm a born lecturer on this topic)...and maybe others...

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I can hear "coons" if I listen for it... I can also hear "f'ing punks"...
I would lean towards "punks" if asked to testify... but, not definitively...
Have you ever watched those cheesy ghost hunter programs?... where they play a garbled noise, and then tell you it is saying "get out!"... then you listen again and you can hear "get out!"...
That's a normal human response... much like seeing a face in the moon, or a bunny in the cloud shape, or the curtains...
...(listened again)... not hearing "coons"... I think he's saying "punks"... 80% positive...
That doesn't absolve him of killing,.. or even racist motivation...
I just don't think I hear "coons"...
I do still think...
... if I had been in Zimmerman's shoes... that young man would still be alive... and so would I... and no one would be burgled, bludgeoned, molested, or accosted because I didn't kill him...
I still blame Zimm for that...

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I think he acted unreasonably...