In no way do I intend to justify or defend the attacker here, but I do feel the need to point out that "anti-islamist activist" is a thin veil for "right-wing nationalist".
Same goes for Pax Europa. They may describe themselves as "informing the public", but they're a a right-wing extremist group who are under observation from the "Bavarian Office for the Protection of the Constitution", which, if you know anything about German politics, could be described as "a little bit blind in the right eye", i.e. it takes quite a bit for them to even start observing threats from the right.
(Only reason I'm adding this as context is because in the comment above, only the heavily euphemised descriptions were cited.)
No, not the LEO. We're talking about the guy the attacker was in an argument/brawl with before the LEO arrived.