User blog comment:Grimmival/Is Hank a Grimm?/@comment-1966944-20120507234023/@comment-1509826-20120511233631

True, but maybe some are better at controling it than others, after all its possible he was strong willed enough to keep his form, that would be a useful abbility, as they can't sense grimms unless the grimms sense them, so he would have no idea who was or wasn't a grimm.