 Johnson was arrested in the late 1940s after a policeman overheard him calling to his son in Wiradjuri - it was forbidden to use Aboriginal languages in public - and he was detained overnight in a cell.From that day on, his grandfather refrained from speaking his native language in public.He has been crucial to the reconstruction of the Wiradjuri language along with Dr John Rudder, with whom he travels among the Wiradjuri people, teaching their language.