That isn't a good test of astral projection but it could be a good test of telepathy. He knows the word, so someone with telepathic ability could pick it out of his brain without ever leaving their body.
Also, astral projection and remote viewing are not the same thing. There is some overlap. In remote viewing you stay in your body but are sending your mind's eye out looking. mental projection I've heard it called in some books.
With astral projection you leave your body. It's like the peanut leaving the shell and when you look behind you, there it lays.