Depends entirely on whether he imagined the spitball was an artillary shell or not.
I'm sitting here giggling cause I used to defend my little playground battler and he grew up and became an artillery gunner. LOL!!! He didn't use spitballs though. But you can light golf balls by shooting them out of a cannon. *ahem* Goodness, this school is lucky my kids are grown and were never in their district.