> But I would not trust a government employee.

That isn't really a choice. You can either going along with what the employee says, or a) appeal their decision b) change the law, or c) abide the consequences. They also presumably have records.

As for why this path, California has a prescriptive right of access--if people have customarily accessed the beach through this path (for 5 years, I think), then they are permitted to continue doing so. The California Constitution also doesn't just make the beaches public, but explicitly provides for public access to them:

   No individual, partnership, or corporation claiming or 
   possessing the frontage or tidal lands
   of a harbor, bay, inlet, estuary, or other navigable 
   water in this state shall be permitted to
   exclude the right of way to such water whenever it is 
   required for any public purpose and
   the Legislature shall enact such law as will give the 
   most liberal construction to this
   provision so that access to the navigable waters of 
   this state shall always be attainable for
   the people thereof.