Text from document ending up in Zimbra-mail by accident

Dear All,

We are using Zimbra ( zcs-7.2.0 ) on Centos6.3 - both the server and the laptops people are using is Centos.
We have some 160 people using this and it goes without much trouble.

Now I have a user who reports having a LibreOffice file open with some text on it, and that text ending up somehow in a Zimbra mail.
My first idea was to disable the ctrl -v shortcut on his laptop, assuming he accidently copied this to the mail.

But as is shown in the attached screenshot, somehow the text - I blacked it out for privacy - ended up above the title on top.

Does anyone have a clue on how this could have happened?

Many thanks for anyone who can offer any advise

Greetings, J.