they didn't "just" take down the site, they took down the whole domain

Even google safe search isn't blocking you site per-se, it just adds a very annoying "this site is not safe" dialog you can "somehow" bypass (but most people wont and don't know how).

Like if this where the main site of a company (which it very much could be) this would also have taken down mail, all APIs, all Apps relying on such APIs.

so no this is absurdly unreasonable actions

that they seem to neither know nor care that this makes it impossible to "fix" false positives with google isn't helpful put this in the area of high levels of negligence which can get you into a lot of trouble in the EU