Interestingly, the Latin they were speaking in the film was liturgical Latin, which I’m pretty sure was developed hundreds of years after the first centyry.
...aside from the Italicisms in the liturgical form (softening of C and G, and supposedly the change of V from a W sound to what we know today), it is hardly appropriate to speak of it as a separately developed language, because it is not...were it so, it would be more like one of the early daughter languages developed from late Vulgur Latin...
essentially, it is Caesar’s Latin with some daughter language pronunciation...an improvment in my opinion...speaking of Caesar, those who insist on ‘correct’ classical pronunciation would have us say “wayni, weedy, weecky”...ugh...
I actually prefer the sound of the classical pronunciation, despite the fact that "Ceasar" and "Cicero" are pronounced "kaiser" and "kickero." Nonetheless, when the Gaylords recorded Veni, Vidi, Vici, I'm glad they used the liturgical pronunciation.