"Predicted" a possibilty that was being widely covered in the mainstream media at the time, and he failed to comprehend that if you destroy a nuclear testing facility with conventional ordinance that you'll create radioactive fallout due to the dispersal of materials in said facility.
If you'd told anybody who watched that at time that he'd be elected POTUS in the future, they would have laughed.
Another disturbing observation from that clip is how much more lucid he seemed back then and how much his command of the English language has deteriorated.
A lot of what he'll say just comes from common sense, he's not an expert in those subjects and doesn't claim to be. A president rarely is.
Trump had been teasing a run for president long before this video. The fact that he was being taken seriously at the time from a political standpoint, means it wasn't so far outside the realm of possibility in peoples minds back then.
He sounds practically the same to me, perhaps a bit more bombastic now, which I've seen him tone down when he's not on television.