A crawler is a data processing machine, nothing more. therefor you are disrupting dataprocessing through data. If you think its not thats ok too.

Nah it’s definitely disrupting data processing, even though at a very low-key level – you’re not causing any data to become invalid or such. It’s the intent to harm the operator that’s the linchpin: “Jemandem einen Nachteil zufügen”. “Jemand” needs to be a person, natural or legal. And by stopping a crawler you don’t want to inflict a disadvantage on the operator you want to, at most, stop them from gaining an advantage. “Inflict disadvantage” and “prevent advantage” are two different things.

I would still advise to contact your lawyer in germany if you are thinking about hosting a zipbomb

Good idea, but as already said before: First, you should contact a sysadmin. Who will tell you it’s a stupid idea.