The method used, of getting access to a fugitive resource, determines whether it was legal.
If you shoot a water tank, on someone else’s property, so the water will flow to your property, then that is no different from accessing oil that is in a pool under my land, via tunnel, from someone else’s land. You would have no legal right to it.
The same would apply to scaring a fugitive off my property onto yours; it does not apply to the rule of capture. You cannot claim ownership of something that you gained by trespass. It is not a fugitive resource, if it does not flow there naturally.
You could go shoot at all the cows or horses from someone else’s property, or wildlife off a protection reserve, and corral onto your property, but that does not make them yours.