Article mentions the bulk of the bill was a "trauma activation". This is an alert from the EMS units to the hospital that they are bringing a patient with indications of trauma requiring additional medical resources to be diverted. The reaction and resources differ per trauma facility. SFGH is a level 1 center [1]. There are better news sources that describe the trauma system within the context of this story.
My opinion based on limited information within the article is that the field EMS suspected a closed head injury. The trauma "doctors at the hospital quickly determined that baby Jeong Whan was fine". If the baby had an MRI instead of a medical exam by a team of specialists, the headline would lose some weight.
The fee is to staff ED specialists 24/7. I believe the better question is: "should we charge for resources that were used but stood down after initial assessment by the trauma team?" From the perspective of the EMS field, there are protocols that describe tbe patient condition, mechanism of injury and other indicators which dictate a trauma activation.