If this was an exam for a freshman/sophomore course, I might believe it since lower-div classes at Berkeley have an exceptionally wide audience with non-uniform

If this was an exam for a freshman/sophomore course, I might believe it since lower-div classes at Berkeley have an exceptionally wide audience with non-uniform levels of prior mathematical experience. However, if this was an upper-div course, I highly doubt your anecdotal experience holds true in general. Source: majored in math at Berkeley, went to MIT for grad school.