but then again, he probably lost his Canadian citizenship, ten years after he returned to the US and once again was a Cuban citizen. Actually, he might have always been a Cuban citizen, with dual Cuban/Canadian ciitzenship during that 18 year period.
Loss of Canadian citizenship generally occurred in the following cases:
o naturalized Canadians who lived outside Canada for 10 years and did not file a declaration of retention
see: http://en.wikipedia.org/wiki/Canadian_Citizenship_Act_1946
Senior actually renounced his Canadian citizenship when he received US citizenship (maybe before when he applied), but in his bio he says he renounced Canadian citizenship.
Which is additional circumstantial evidence that he renounced his Cuban citizenship when receiving US citizenship. Otherwise, he would have renounced both at that time.