Derek Hough opens up about how hard it was to relive memories of wife Hayley Erbert’s health scare while watching ‘I Am: Celine Dion.’ The ‘Dancing With the Stars’ judge shared a throwback video on Instagram of a time when he and Hayley met Celine before a concert. Derek writes in the caption that he could ‘barely re-watch’ the singer’s Stiff Person Syndrome seizure captured in the doc, because it reminded him of the seizure his wife had just months ago, that left her hospitalized for weeks.