That sounds like you maybe figured out how to puncture the gas tank and it left a leak. There’s a technician who smokes next to it and will blow it up if it’s leaking. It’d seem like it randomly blew up. Good news if true. Maybe a shot right to the spigot causes a leak.
I’m not sure that the leaves blocking the view to the lawn mower would actually stop bullets, so the Ezra kill might still be possible… though it also might be hugely untenable. You’d either have to blindly shoot the mower tank to cause a leak and then blindly shoot the gas slick, or you’d have to prep it with a shot to spill the gasoline.