User blog comment:Grimmival/Is Hank a Grimm?/@comment-1966944-20120507234023/@comment-1509826-20120508164805

I personally always saw it as fitting with whats been established, don't forget the wesen in question has to get worried, scared, angry or some other form of stressed and thus lose a bit of there control before nick could see them. Thats been established since the start, and it just fits there personalities, all were so good at there jobs, and covering themselfs, that they didn't get stressed enough. Later nick could see the geier's but he couldn't at the time as they could keep control of themselfs. Its a clever idea that allows the writers to get away with not revealing who the villain is till the end in some stories, and at the beinging in others.