Rey Mayoral, the new temporary principal at West Marin and Inverness Schools, was caught in a nearly decade-long lawsuit with a former colleague from a school district in Oregon who described sexual assault and accused him of sexual harassment and retaliation. 

Though the case was ultimately settled, an appeals court decision from 2009 found validity in some of the claims of the plaintiff, a counselor who worked with Mr. Mayoral at McKay High School in…