Not really. I think the speaking was the Unown's part of things, because with the exception of Team Rocket's Meowth and Maiden Peak Gastly, all the other Pokemon who talked are Psychics, and Unown are Psychic, so I think that played more of a part than anything.
Besides, since he was an illusion, the writer could make up anything and he did. Heh.
That and the voice of her father placated Molly as the Unown were using her essentially, in fact it wasn't until Ash that make her wise up.