He isn't employed as a research professor. He's employed as a lecturer. Berkeley does have a lecturer position with security of employment (commonly called lect

He isn't employed as a research professor. He's employed as a lecturer. Berkeley does have a lecturer position with security of employment (commonly called lecturer SOE or teaching professor). These positions are evaluated on teaching rather than research. I don't know how common it is in other departments, but I know the EECS department employs several teaching professors (which means many classes, especially 61A and 61B, are taught by professors whose primary job is teaching).