Replies to mention notification emails does something funky

[Jason Adams]

Here is the scenario.

A customer opens and issue and I am assigned. 

I @mention another support rep in an internal comment

The other support rep replies to mention notification email with some internal information and it is added as a public comment and thus the customer gets a notification a comment was added. 

Aside from trying to enforce a policy to not reply to mention notification emails, is there any way around this? I would be happy if the reply created another internal comment but can not see where I can make this happen. 

Thanks in advance.