On the subject of Amarillo pronunciation...this is just a Texas thing. I live in Austin, near a street named Manchaca (pronounced "MAN-chak" by locals"), and we have a street named Guadalupe (pronounced "Gua-da-LOOP" by locals), Koenig ("KAY-nig"), and Burnet ("Burn-it"). Oh and the city of Buda, Texas? That's "Be-YOO-da". Hell, even people in Amarillo know how it's said, they just follow the old "We've always said it this way, so why stop" mentality.
Point is, it might not be entirely a racist thing for a Podunk Sherriff to mispronounce words, just local colloquialisms they never unlearned because they're too damn stubborn.