Scott and Jordon spent over one minute in the elevator to go down two floors. The hospital is three stories tall and Jordon got on after Scott, so he would have come from the third floor. Hospital elevators are fast for the purpose of getting staff and patients where they need to go quickly. It would never take over a minute to go two or even three floors.
For a fireworks display with large shells such as are shown here, the display is set up well in advance of any spectators being allowed in the area. This is a safety measure that allows for the shells to be loaded in the tubes and covered so that a misfire doesn't detonate nearby shells, as is what was apparently happening here.
Even though firemen in turnout gear are seen walking through the area with the injured, a man using nothing but a hand-held fire extinguisher is fighting the burning trailer full of fireworks and no firemen are seen attempting to do anything. This occurs even though enough time has elapsed for several physicians to have arrived on scene from the hospital fully prepared and arriving via a paramedic ambulance.
Although the date of the story isn't specified, judging by the title and air date a couple days after Independence Day, plus characters' comments that it is very hot outside and a park festival included fireworks, it is reasonable to assume the events are supposedly happening in early July. That would make one of the characters having front row tickets for a Spurs-Warriors afternoon game a goof. The word "playoff" was not used, so a regular season game between those teams, who are both in the Western Conference, could happen no later than mid-April. Even if it was a playoff game, the latest they could play would be in the Western Conference Finals, but those are usually done by the end of May. The NBA Finals go into June, but the Spurs and Warriors could not play each other in the NBA Finals because they're in the same conference.
Two of the characters are worried about paying their medical bills related to injuries from the fireworks accident. One of the doctors offers to ask a veterans' family support organization to help. Surely any professional, like a doctor, would know that the city would have required liability insurance for their park event, especially from a fireworks vendor. Any victims of what obviously was the fireworks company's error would reasonably expect their hospital bills to be taken care of, at minimum. Plus, any reasonable person seriously burned in that situation would be highly motivated to sue someone for much more than any health care costs.
The firework tubes shown on either side of the stage show them to be complete and having the protective aluminum covering on the tubes. There is no explanation as to why all of the shells would spontaneously ignite when the protective foil is in place to keep this exact thing from happening.
Anytime that a public event such as a concert/fireworks display is put on by a city, paramedics and firefighters are stationed on scene, none of which were visible here.
The emergency medical treatment in the field for burns consists of the three C's - "Cool, Cover, and Carry". While the treatment in the park does include pouring water on the victims burns to cool, the patients are seen being pushed through the ER on gurneys and riding in the elevators with their burn areas fully exposed.