Insufficiently secured or own fault?

Google for: Leitfäden zur Absturzsicherung - BG Bau

There you will find some reading material for preparation

If it were adequately secured, this wouldn't have happened either - that's how you have to see it. What about children? Curious onlookers on construction sites? You have to guard against such eventualities...

Oh yes, our identical shaft is currently covered by a bucket - even more poorly secured ;).

It doesn't really matter what we think anyway :)

If I put my hand into the running circular saw, is that also inadequately secured... you could also move the bucket aside and fall into the shaft. Even warning tape doesn't help against intentional behavior....

A similar case is possible here... A construction worker climbs on the bucket... it tips over - he falls down and breaks his hand? Who is to blame?

It basically doesn't matter what we think anyway :)

That's somehow true... but when someone is wrongfully accused in my eyes, just so an employer or insurance can try to get out of trouble... that's really annoying. Accidents happen and I also feel sorry for the poor guy that he got injured like that... but now I'm supposed to justify myself and take responsibility for his "stupidity"...

As I said, you don't need to argue with me - you should speak to the BG as soon as possible.

How deep is this shaft from the shaft opening?

The shaft is maybe 1 meter deep + 30 / 40 cm for the opening protruding from the ground.

Exactly, the BG is your insurance at this point (unless you are accused of contributory negligence, for whatever reason).