, so I don't understand why you can't just train in both places, learn from both places, and do things according to the methods of whichever sensei you have at the time......
there's no reason not to keep on learning what you can from both places.
I believe the problem is that in order to continue to train at both places he may need to:
a. lie (eventually get caught out)
b. upset the southern dojo sensei and deshi
Although perhaps Matthew is right. Be honest, train at both places and the southern dojo people will have to learn to get over it. (or boot you out)
Be a bridge builder !!!