When Henry starts to sit down with Frank after asking for some crossword help he has his pencil in his right hand. Next he's shown sitting down with the pencil in his left hand. The next camera angle it's back in his right hand.
Putting Kerosene in a diesel engine will not harm it. It is common practice in some colder places to mix 10% Kerosene to thin it out in colder weather. Also, Kerosene was places in a tank of a non-running truck. All he would need to do, if he was worried about it, would be empty the tank.
There not an 86th Airborne unit in the US Army. There was an 86th Infantry unit. They might have meant the 82nd Airborne.