Look at the word "corpsman". Sound it out. Corpse-man.
That's it exactly. I wasn't sure how to make my point, but you just made it for me. It's as if he's never heard this word spoken before. Naturally, it's nothing of ground-breaking importance, but it does indicate a certain lack of familiarity with (or interest in) the military and its jargon. "Corpse-man," reflects actual ignorance of a
semi-obscure word common bit of military jargon. This is an, admittedly small, disappointment from a commander-in-chief.
I guess I see "nucular" as an unconscious switching of vowel sounds. I hear that sort of thing all the time, in various words, from people with varying degrees of education. It's so common, I can't think of any examples that even stand out in my memory. It's quite common for people to pronounce words the way other people do, rather than sounding them out letter by letter.
But, hey, I'm sorry. I've just never been able to climb aboard the nucular-bashing bandwagon. I have too many other grammar/spelling/syntax errors to get annoyed about. Also, I suspect most people on said wagon were also mispronouncing the word until someone pointed out that Bush was doing it. Present company excepted, of course.