Germany is not some magical place where people never work more than 10h. That part of the law you quoted is only about regular shifts, whereas OP's example of b

Germany is not some magical place where people never work more than 10h. That part of the law you quoted is only about regular shifts, whereas OP's example of being on site and basically waiting until something happens would very much fall under § 7.4, as being on standby, also it doesn't sound like this happens every week. Yes, in general I won't complain, certainly not about those restrictions - but it's simply wrong to act as if no one had exceptional longer shifts, or what the OP did would be illegal.