Overturning an appeals court in a unanimous opinion Thursday, the California Supreme Court ruled that a trial court did in fact have authority to impose a $2.5 million sanction against the City of Los Angeles for a pattern of discovery abuse and misconduct in litigation against a contractor.  The zigzagging case dates back to 2010, when the city of Los Angeles hired PricewaterhouseCoopers, one of the biggest accounting firms in the world, to modernize its billing system for the Department of Water and Power. When that new system and software was introduced three years later, it caused chaos, undercharging some customers while significantly overbilling others. Ratepayers filed multiple class actions against the city. Los Angeles in turn sued PricewaterhouseCoopers.