Jebediah had honestly been expecting to ram the thing-before his passengers showed up and demanded a ride. So this changed things. But plan A could still be used as a bluff to cover up his real actions, so he kept barreling in like a madman, leaning the Helicopter more and more forward to gain more and more speed, even as he twisted it's flight path into a wild and unpredictable twist.

"Like heck you're driving! But you might want to hold onto something, before I flip this thing!"

...that was the worst possible position for a helicopter to be in. Flying inverted in a chopper was a good way to slam yourself into the ground. And that's if you don't stall the engine or break off all the rotors from the strain. It was therefore, the last thing they would be expecting.