AFTER WORKING FOR MORE THAN 10 years at The Dallas Morning News, where she made a reputation as a dogged investigator on such high-profile stories as the Walker Railey attempted murder case and the Robert Tilton church scandal, Olive Talley was looking for new challenges. She’s found them as reportorial producer for ABC’s “Prime Time Live,” where her job is to find and develop stories for anchor Diane Sawyer to do on air. “The news gathering and reporting isn’t much different [than print],” Talley says. “But the storytelling is much different. The facts and information have to be there, but the pictures do, too.” The biggest change: “There’s a lovely view of the Hudson River from my roof,” Talley says-but between negotiating the subway to work and fielding 2 a.m. voice mail messages from Sawyer, she hasn’t had much time to enjoy it.