Notice, too, that Jackson said...
"That I think would SEEM to be quite presumptuous to say that we are the only spokesperson that God is using."
In other words, 'To you (Justice McLellan, Angus Stewart, and the Royal Commission) it might SEEM to be presumptuous but it really isn't, because you don't understand the truth like we do, and if you did understand the truth you would agree that we ARE the only Organization God is using.'
I suspect that Jackson was guided by the Legal Dept on how to respond to such a question. As mentioned, he was being sneaky and using the Theocratic Warfare Strategy, lying to the Commission after swearing to tell the truth.