If they're writing cyclists up for a violation of vehicle code 22450 for not putting a foot down that sounds incorrect. The law only says vehicle operators have to stop (as in complete cessation of forward movement), not that vehicle operators have to put a foot on the ground.
Originally Posted by www.leginfo.ca.gov
22450. (a) The driver of any vehicle approaching a stop sign at the
entrance to, or within, an intersection shall stop at a limit line,
if marked, otherwise before entering the crosswalk on the near side
of the intersection.
If there is no limit line or crosswalk, the driver shall stop at
the entrance to the intersecting roadway.
(b) The driver of a vehicle approaching a stop sign at a railroad
grade crossing shall stop at a limit line, if marked, otherwise
before crossing the first track or entrance to the railroad grade
crossing.
(c) Notwithstanding any other provision of law, a local authority
may adopt rules and regulations by ordinance or resolution providing
for the placement of a stop sign at any location on a highway under
its jurisdiction where the stop sign would enhance traffic safety.