I am not so sure it was deliberate distortion.
Any journalist or historian must pick and choose which facts they believe relevant to the story.
I suspect to this editor’s perception the unedited tape showed clearly Zimmerman’s racism. So all he/she did was edit out those distracting bits of dialog in between the important parts. Didn’t change the meaning at all.
I, of course, disagree with that perception, as I suspect would all fair-minded people. But for someone focused enough on their cause, I can see the possibility of it not being concious deception.
Maybe, but it doesn't matter. The people must be educated not to do this; same as, as long as we're being racial, Southerners were educated no to use certain words.