Hello,
Do you have any more pictures of this "slander/harrassment?

 

With this, I have to say that it is not enough evidence for any action to be taken. If you happen to find a series of pictures of this slandering/harrassment, please feel free to file another complaint.
If this user is bothering you, the best thing to do is to use the /ignore command that we have for these types of situations.

Locked. Lack Of Evidence.