Hello JsWill,
(Just in case my previous post didn't make sense, I meant is it CRB to gather food and leave town after.)
This is not (obviously) a CRB; but as you said, under certain circumstances, it's a CRB. For example if your character spawns in a forest, and just gather a lot of wood its first too cantr-years of life, and then, travels directly with a bunch of wood to a place where you have another character and you know the town is in extremely need of wood; (it's worst if, also, your character doesn't have a map for example).
So just gather food during a couple of years without talk and then just leave, of course is not a CRB
But sometimes (you know that after some years playing, some players develop a capacity to detect this strange behaviours) it has to be investigated to be sure there is not a breach behind that.