In the same scene, citizens of Adventure City cough from the smoke from the fire extinguisher, which is part of the above mentioned Failed Attempt at Drama. This shows how Humdinger cares for himself, not the others around him.
Why does Chase claim his biggest fear is the dentist when trying to comfort Alex in the "What Do They Fear?" Episode in the main show, while this movie demonstrates Adventure City is not only his biggest fear but a full on Trauma Button? Well, obviously this was partly because Chase was actually nervous about going to the dentist, making said fear situationally appropriate. But The Movie also demonstrates that Chase hates the idea of being seen as a scared child instead of a hero so obviously he'd avoid showcasing his Trauma Button to either Alex or his teammates.
A very nasty bit in the climax. Ryder ended up in life-threatening danger because Chase let his fears control him and while he's able to pull himself together and save his leader, imagine what might have ensued if he hadn't been able to summon his courage or missed his mark and Ryder DIED? Chase would never have forgiven himself and the Patrol probably would have fallen apart.