I just watched the play again. What the ref might have seen was Wayne's left hand/arm hitting Hobbs' helmet/facemask as he (Wayne) tried to jump up and make the catch. There definitely appears to be contact. And Hobbs obviously is not playing the ball, so that might fall under Rule 8, Section 2, Article 5(a) -- "(a) Contact by a defender who is not playing the ball and such contact restricts the receiver’s opportunity to make the catch."
Now, some might argue that Hobbs didn't initiate the contact, since it was Wayne's attempting to make the catch that caused him to reach up and hit Hobbs' helmet with his arm. But perhaps that's Wayne's right to the ball, and any contact with a defender who isn't playing the ball therefore is interference.
So, the question is, did Wayne's left hand/arm make contact with Hobbs' helmet? And if so, does that constitute pass interference simply because Hobbs wasn't playing the ball? If the answer to both questions is "yes," then it was a good call. If not, it was a bad call.