Let's face it - some so-called electricians ARE hacks and destroy the reputation of the entire trade. In Vienna there seems to be a shockingly large number of them. Recently I had to walk a journeyman with 30+ years of job experience through wiring an RCD like a kindergarten kid!
He seriously didn't get it why the RCD would trip if the phases were connected to the RCD and the neutral taken from elsewhere. An identical situation would be a GFI or GFI breaker in the US. Even an apprentice should know that if you are downstream of a GFI outlet you can't just "borrow" a neutral from an unprotected circuit! He'd also happily connect the line side to the screw shell of an Edison fuse holder (Neozed fuse).
