Bottom line—the Secret Service cannot delegate authority or responsibility to local authorities.
If they ask for and receive local assistance the Secret Service is responsible for controlling and monitoring those activities.
There are no excuses.
No scapegoating of locals is allowed.
By statute.
This seems like it implicates Biden and his DHS:"(e)(1) When directed by the President, the United States Secret Service is authorized to participate, under the direction of the Secretary of Homeland Security, in the planning, coordination, and implementation of security operations at special events of national significance, as determined by the President."
What about the deputy who went home? Was he ordered by the SS or just decided it was too hot?
The SS failed in their duty or planned to fail Trump.