Earlier quoted context omitted.
German law covers this in §32 StGB ("emergency defense"), which includes emergency assistance. If people were reasonably convinced that he was threatening others, they're done & out clear. P.S.: in German law, it's actually a crime to _not_ render assistance to others in danger - StGB §323c ("failure to render assistance")
> If people were reasonably convinced that he was threatening others You're the first person to suggest that he was threatening others.
It doesn't matter whether he was intending to threaten, or ignorant about the rules, or just stupid. If he leaves the boundary of socially acceptable behaviour (yes this is subjective and established by the community) then he may full well get evicted, and with force if necessary.
On the legal side, a judge or jury would repeat that consideration, and establish whether his behaviour was beyond acceptable for the context he was in. Not by the judge's or jury's social standards, but by trying to understand the situation and determine whether the crowd acted "reasonable." Since there's quite a bunch of people involved in his getting kicked out video, I would wager a guess that there was consensus that his behaviour was inacceptable, and a judge/jury would side with that.
German law doesn't do "I spilled hot Starbucks, now I sue Starbucks for damages". You're expected to have a brain and some level of common sense (or be certified psychologically ill, if you prefer).
Relatedly, the "they should've called the police" argument is legally wrong in Germany too. The allies were pretty pissed off after WW2 and wanted to eliminate the "bystander" excuse for people who watched Jews getting gassed. That's where the "failure to render aid" law comes from. Of course, you're not expected to endanger yourself, but - say, there's an average guy assaulting someone, and you're travelling in a group of 5 reasonably muscular, capable guys... your excuse to not step in is gone.