KK
Was Stan stabbed, impaled, or the like by the pencil?
Was any form of machinery relevant to the mechanism of Stan’s death?
Was Stan writing something when he died?
You mention if he was holding something else he would have lived… would he have lived if he was holding a pen? a specific other non-pencil object? a different pencil? nothing at all?
Stan was just sitting there, holding his pencil, minding his own business. A moment later, there was a crack. A moment after that, he was dead. How did he die?
I have no specific non-pencil object in mind, so NO.
Did somebody mistake the pencil for a different object?
Did they think it was a gun?
Did Stan touch another object with the pencil?
kk
Did he try to pick up a gun with a pencil?
Was he investigating a crime scene?
Did he touch the pencil to something electric?
Did Stan mistakenly think that the pencil would protect him from a dangerous thing?
Somebody attacked him with a sword. If he had a pen he could have protected himself. But it turns out that a pencil is not mightier than a sword.
Was he shot by a projectile?
Stabbed or impaled by anything?
Blunt trauma?
crushed?
drowned?
asphyxiated?
drawn and quartered?
Did he fall for a fatal distance?
poisoned?
organ failure?
Did the pencil make Stan more visible than he would otherwise have been?
Was the object that he touched with the pencil paper?
Was it something else that he was using the pencil to make marks on?
Was he using the pencil to do something other than writing / drawing / making marks?
Was he engaged in carpentry, home repair, or similar?
Did he die because he made a mistake of some sort?
NO to all of those.
NO
NO. 
kk
He touched another object with the pencil, was he impaled by that other object? By an object propelled by the object he touched?
Did the pencil make an electrical connection of some sort?
Was he impaled/stabbed by a falling object?
** Stan was just sitting there, holding his pencil, minding his own business. A moment later, there was a crack. A moment after that, he was dead. How did he die?**
Stan was sitting, outdoors, in a city when he touched an object with his pencil, whereupon that object stabbed him.
Was the object alive? a machine?
Was the object designed to stab things? Did the object malfunction when he touched it? Would a reasonable nearby observer have cautioned him not to touch the object with his pencil, because it was dangerous?
Was the object an animal? Something with a horn? A tusk? A tooth? A claw?
NO
It’s a knife. I am aware that a knife may be a simple machine, but I have been answering no to machine questions because it is simply a knife.
So would they caution him not to use it on his pencil? No, Stan was an adult. A child? Yes, I would tell my kids not to do that…
Was it a ballistic knife? A spring loaded blade that was triggered by Stan touching it?
Was the reason the pencil was touching the knife because Stan was trying to sharpen the pencil?
no
yes