When you explain the idea, Skyler looks skeptical and Casey recoils, but Vance loves it. Since Vance runs the show, you hop outside with the propane tank. Then you load your weapon and switch off the safety. As you do so, Vance lurches out of the passenger door and hightails it for the cover of the rockfall. That's not a bad move, as you suspect the tyrannosaur's jaw is fully capable of taking a chunk out of the camper and grinding it to bits.
It's clear, however, that the beast isn't simply going to get distracted and wander away, not after Vance stung it with some of his shots. You open the valve on the propane tank and light it. After setting it on its side on the ground, you give it a good kick to send it rolling toward the T. rex. You raise your gun and aim, concentrating like you've never done before. Now or never.
The tank rolls straight and true. You hold your fire until it's right beneath the tyrannosaur's belly.
Pull the Trigger