I didn’t know about that 5 year rule for Canadian citizenship but I checked and that was in force in 1970. OTOH with his records sealed except for his mother’s BC, we don’t know when they moved to Canada.
The only thing I had heard/read was that shortly after the Dallas incident (’64), the family moved to Canada for whatever reason... I can’t back that up with any certainty so we don’t really know exactly when they moved there.
Damn. It would be good to know one way or the other.
You want more confusion take a look at the following links.
They cover the some info in some degree or another.