It certainly isn't something an MP should be involving themselves with.
If the stalking thing is true.....and we all know the left's habit of over egging definitions to justify their actions....while giving no leeway to their opposite.....but if this guy genuinely is a nut job.....then I can understand it.
However, we can't have this from MPs and yes you are right, it wasn't self defence.
I never had a problem with Prescott punching someone for hitting him with an egg because he didn't instigate the action. But this was just violence directed onto the individual.