Stop the sender or defaultReporter being added as a watcher
Scenario
There are two reasons users would be added as watchers.
The default behaviour is to add sender as watcher
The user in question, since JIRA 5.0.3 has a particular user preference set by default, see this question.
Solution
Right now if the user has the option set, then JEMH won't unpick that. If the user does not have the option set, then JEMH can add/remove the associated user as a watcher through the option above.