Complex sentence: TFEU article 49 says states are exempt from infringing others'freedom of establishment when they exercise "official authority", but this did an advocate's work (as opposed to a court's) was not official.
Split into simpler sentences: TFEU article 49 says states are exempt from infringing others'freedom of establishment when they exercise "official authority". But regulation of an advocate's work (as opposed to a court's) was not official.