I’m really glad he cleared that up for everyone.
Since neither the Supreme Court nor the Congress nor the Constitution has declared a clear definition of natural born citizen, I am really happy to hear your brother has solved this vexing issue for everyone.
There's nothing to solve. The British citizenship of the Founding Fathers' parents is the reason they exempted themselves from the Natural Born requirement. TWO parents of United States citizenship (not necessarily Natural Born) are required for a US citizen to also be a Natural Born Citizen.
Do you honestly think they would have wanted "anchor babies" to be president? The real possibility of a CIC with divided loyalties would have been suicide for this fledgling new nation. Think man, think!