Re: "any organisation has to adhere to the labour laws . . ."
I'm not going to defend the European Institutions laws / staff rules - I will remark though that all of these Institutions mandates are created and approved by each of the Member States Governments - its therefore also a national responsibility to correct things if they are not fit for purpose! In the case of ridding the IPO, which is not an EU Institution, of its leader it seems the same is true. With the exception of a few honorable exceptions the responsible administrations are not living up what I would expect their electorates to demand from them.
Also its incorrect to say that EU bureaucrats don't pay tax - they don't pay tax in the Member State they work in but they do pay an EU income tax - http://ec.europa.eu/civil_service/job/official/index_en.htm. However, in the case of the IPO which is not an EU entity, it may be that no income tax is paid.