It's not so much a rotten police but rotten politics.
During normal days they are staffed with about ten people at the train station, that day they has 55.
That's the federal police, but the police in general is understaffed unless they prepare for big events by asking for support in advance.
Now unless they should use fortune tellers, they could not quite expect this to happen, could they?

I also heard that people could only be sent back for crimes that have a minimum sentence of three years in prison.
As of this year they seemingly changed it to one year minimum sentence, but that still allows for a lot of theft etc. without any effect on their asylum application...