"I do wonder how channel 7 knew he was being arrested and had a film crew there to record the incident given that 1 hour after they received the received historical investigation information from a relative they attended the house and arrested him. ( it was shown on the local news with sound grabs)"

The police were at his house the day before hus arrest. The police made a statement about arrests being likely. They also mentioned they had solid evidence about a pedo ring. The media would be staking out his house waiting..

The police knew about the historical info long before the 1 hour before they arrested him. They had accessed medical records taken at the time etc and investigated other info.