That's not he same thing as what Jackson stated. Jackson stated that the JW religion as a whole did not believe in a literal interpretation of the Proverbs "rod," i.e., that corporal punishment was allowed. If crossing a national border is all it takes to allow an interpretation or application to change, then it isn't a doctrine.
For instance: it's legal to purchase and smoke or otherwise use marijuana recreationally in various countries and states but prohibited in others.
If JWs are against the use of marijuana then this doesn't mean they allow their members to use it in those states and countries where people are free to do so. If the JWs are against its use, then that would mean JWs don't use it even in areas where they are free to do so.
JWs freely spank and otherwise physically punish their children in the United States, and the literature as published in the United States reflects this. This means that the JW religion as a whole is not against corporeal punishment because JWs can and freely choose to do it where and when they can if they so choose. If they are in a state or country where it is forbidden, then they don't due to the law. Yet should they cross the border, then they are free to do so since it is not against JW doctrine.