no, not the same thing. Think broader. He migth mentally be ready and prepared to kill, say if he had to, if he got caught, whatever. But planning to kills a specific target is something more. Being ill prepared for clean up litterally means he wasnt set up. He didn't plan it that night, it wasnt suppsoed to happen. And no, it wouldnt have worked at the farm property, they towed it to the hangar to run it there. Power? Fuel? whatever reason it was.If he was "prepared to kill", then is that not a type of premeditation?
Clean up ill prepared could have been because he intended to do the killing at his farm property, not in the truck.
Sorry, I wont ignore hard evidence which supports a theory, or try and explain it away so it suits what I would want a verdict to be.