According to the Californai Vehicle Code (looked it up on
www.leginfo.ca.gov),
21201. (a) No person shall operate a bicycle on a roadway unless it
is equipped with a brake which will enable the operator to make one
braked wheel skid on dry, level, clean pavement.
Maybe "executed by a hand lever" requirement was adopted by some local ordinance. In which case, you'll have to check it out with the local agency.