The Clumber Spaniel failed Crufts because of bilateral ectropion, i.e. the turning out of the eyelid (usually the lower eyelid) so the inner surface is exposed. We see this a lot with dogs with lots of wrinkles and excess skin on the face -- Bulldogs, Clumbers, Bassetts, Shar Peis, St. Bernards, Newfies, Bull Mastiffs and the like. It is one of the reasons Clumber's were put on a breed health watch list.
No word on why the Bulldog or Pekingese failed, but it hardly matters, as health is now a disqualifier for some breeds at Crufts, and if it's for the obvious breed problems great, but if it's for smaller ones great too, as that suggests there may be problems with ALL the dogs being put up as "champions".
Remember these dog shows are for breeding purposes, and ectropion is clear, visible, genetic defect associated with damage to the eye and pain to the dog.