SAN JOSE, Calif. — San Mateo County District Attorney Steve Wagstaffe told the Bay Area News Group on Friday that a report that suspected Half Moon Bay killer Chunli Zhao told investigators his shooting spree came after he was enraged by a $100 equipment bill from his boss was accurate. NBC Bay Area first reported that Zhao was instructed to pay a $100 bill after a workplace incident, an order he disputed. Zhao, 66, claimed that while he was operating a forklift, the vehicle was struck by a co-worker on a bulldozer. Approximately 30 minutes before the shooting, according to the station, he ven…