In one scene as Station 51 was heading to where the man was pinned by the truck, you could clearly see that the squad had only one person in it. How ever, as station 51 arrived on scene, you can clearly see two people are now in the squad.
At the end, when DeSoto sees Gage riding on the back of the engine when it's an engine-only response (the squad is not assigned), DeSoto goes back to the bunk room instead of getting in the squad to follow the engine to retrieve Gage. If the squad had gotten a run in the meantime there would have been only one man riding.