I have to admit, I'm struggling to keep up with all these POIs and how they know each other, but the thing that bugs me is TJ meeting PB the same afternoon William went missing.
Were they good mates? Did they catch up for a beer regularly? If not, why meet for a beer on this day (if that's what they even did!)
It kind of looks like AJ made an appearance at his own home as some sort of sloppy attempt as an alibi, then rushed off to see PB to maybe work out how to cover their tracks.
If neither of them were involved maybe they met up because one of them had gossip about the situation (interestingly, most people assumed that William was lost in the bush at this point.)