The notion that politically savvy dishwashers and outraged busboys tipped off the commies is silly.
It was the famously big gummint friendly DC police or some pissed off lefty who had known for HOURS beforehand that she would be there.
The commies were amenable to the daring move because the APPEARANCE of the spectacle would conform to the preferred lefty narrative of “righteously outraged brown underdogs chase rich Scandinavian top cop from taqueria”.
They had a long time to consult and the media was prepared.
Someone on her OWN staff, most likely, an Obama holdover in DHS.