An argument assumes if it doesn't back up the assertion with reasoning. For an argument to state, it needs more; as written, it wasn't really an argument to begin with. It was just a theoretical supposition.
Thank you for playing the role of the logic police. I guess it can sometimes be unreasonably hard to talk in a simple forum like this in a chill manner without having to deal with people's (IMO) misplaced pedantry. So be it. I'll try to be more scientific the next time.