This is a good example of why slow motion replay is important. At first glance, almost everybody says "no score" because Blue lands mainly on his front at the conclusion of the action.
However, slow-motion replay shows that at the point of initial impact, the upper part of his body lands on his side. This makes it a yuko. As Ezio Gamba points out, people might make the mistake of saying it's no score because they see that lower part of his body flattening out. But what's important is that the upper part lands on his side.