New Evidence aired on Richard and Judy by Mccann sisters?

I never watch Richard & Judy but wonder if the sisters were trying to bask in some kind of reflected glory. If they are telling the truth then this tells me that the friends were involved because surely no-one would have just carried on with enjoying their evening having witnessed a man carrying a friend's child around a dark complex. On the other hand there are so many people who seem to want to bask in some kind of sick spotlight when something awful happens. It would appear that the whole of the McCann family are 'tarred with the same brush' so to speak. Or is it another 'red herring' to divert suspicion!