If COVID-19 had been spreading uncontrolled in California for four months prior to containment measures being enacted, the number of deaths by now would be truly mind-boggling. It's simply not possible for this to have been the case, because it would have been obvious sheerly looking at the all-cause death rate in the state increasing by many times its normal value months ago. This didn't happen, ergo COVID-19 was not spreading uncontained in California for that long.