Late Friday afternoon, Dallas ISD finally revealed it's not renewing contracts for almost 300 of its 10,000 teachers. Trustees approved that measure last night, along with getting rid of two of the district's more than 200 principals, in Mike Miles' most controversial reforms since becoming superintendent less than a year ago. One DISD teacher, Ariawna Talton, still can't comprehend how she ended up on that list. In 2011, DISD said she "Exceeds Expectations." The district told her the same thing last year, too.