I don't think I've EVER heard of a DC admitting that he/she is in your dream... so you've obviously stumbled upon something extra-ordinary. I believe dreams are more than they seem... if this entity says it wasn't your DG, then chances are it isn't. I know my DG because I have this like sixth sense that tells me its him (despite varying appearance). I have yet to even ask him if he is my DG, because it really isn't necessary... he literally guides my dreams when I need him most... fits the description to the tee.