The other difference is that not even a few months ago, police used massive shows of force against people who were unarmed (other than cameras for the reporters among them) and completely peaceful, in the same area.
If you think those three police officers at the Reichstag would have stopped those protestors if they action had wanted to storm the building, you are delusional.
Oh, and not too long before that Greenpeace members actually climbed the Reichstag and unrolled an anti-coal banner. Just that the media didn’t frame this into “an attack on democracy”.
If you listen to him, he's constantly negating what he just said, which comes across as open to interpretation (or completely insane).
No one man or woman is above the law.
Factual information is arrived at by consensus of people. That a certain group of people in this country refuse to accept or participate in the consensus mechanism (or threaten or dismiss that mechanism) then those people are against whatever it is that forms the consensus, such as the constitution, the US Govt., etc.
This is how dictatorships are born and it would do these people well to understand that replacing their made up fears with a dictator is not going to help anyone.
In the end the three officers in front of the Reichtag were able to act this way, because they knew that reinforcements in the form of 100 riot police were only 200 meters away. Badly positioned to prevent the initial compromise of the perimeter, but still there to handle a protest like this.
[1] Video of the incident in Germany. I think the intent of the protestors to enter the building is visible: https://www.youtube.com/watch?v=OdX5952CFTU
Context is important.
As to the infosec problems: legislature is run (even more in the US) by mostly senile, corrupt lawmakers and a staff of technically inept party groupies (or so I guess, clicking random aides linkedin-profiles). I doubt that any nationstate actor needs a raid of their offices to get to their computers (and that's why these people probably get the real national-security stuff on paper...)
A well known protest on a specific day, protesting a contentious issue, while all of the legislative branch is gathered together to confirm the results of the election, which the crowd believes was fraudulent, is an entirely different thing.
Not to mention, the crowd was allowed on the steps near the entrance with no opposition, with reports of policemen taking selfies and even opening a door. Had this happened with the shooter in Zug, would the policeman doing so have been investigated? Would his superiors?
There was meaningful security in place last night in Washington DC: the legislators were evacuated to a heavily secured facility nearby.