You've taken that right out of context. It's not a dismissal but an expression of amazement. As in: "I can't believe that happened!". The article clearly states

You've taken that right out of context. It's not a dismissal but an expression of amazement. As in: "I can't believe that happened!". The article clearly states the result was accepted immediately: > Within a remarkably expeditious three weeks, the paper’s referees confirmed that Zhang, an unknown mathematician, had proved “a landmark theorem in the distribution of prime numbers.”