What does the electrician do during the shell construction phase?

As far as I know, the steel bands must be connected with a "bolted clamp." With us, it was crimped.

Whether this was done with V4A steel in the concrete... I cannot say. At least from the outside, it is.

There is no documentation or pictures.

My construction manager only points out that I should have taken care of it!

Well, it doesn't quite work like that. The construction manager must issue a `construction management statement` in which he confirms the correctness of the execution. The contractor must also issue an `installer’s declaration` confirming the same. This includes measurement protocols.

Hoihoi... we are also building through a developer and now we have the following problem..

If you are building through a developer, that is NOT your problem. The developer only sells you a piece of house on land, hopefully according to the applicable regulations. Or are you building with a general contractor/subcontractor? Then I would check whether the contract states that you have to take care of this issue. Best regards K1300S