According to FReeper 'Hon,' Turnipseed has acknowledged that he wasn't present on base himself during much of the period in question, so it was quite likely he wouldn't have seen Bush. The media simply aren't reporting that part of his statement.
Turnipseed said he didn't realize, years ago when he agreed to an interview with a Boston Globe or NYTimes reporter, that he would be talking to a Bush hater!
I think there's a problem with your idea: What if no one responded as remembering Bush at drills in Alabama? It's quite possible no one would -- people die, forget, are oblivious to the news story, or just plain don't want to come forward, only to be immediately set upon by the Bush-hating media, who would subject any such witnesses to the worst anal exam of their personal lives.