Are you sure? I have searched and searched for verification that his parents were not citizens when he was born and I cannot find it anywhere. You very well may be right and if they weren’t, he is NOT eligible.
I’ve read it a number of times, that they had esacaped from Cuba but were not yet naturalized; either one or (IIRC), both. I have read some speculation by (someone?) that because Cuba had some sort of protectorate or like status, that Cubans qualified as citizens but I think that’s utter nonsese.