Think he could have requested private conversations with the police.
No reason why AE & the rest should be listening.
The police or Bamber can talk to them afterwards.
Maybe he was getting more confident. Several hours after his 3.26am call. Or thought the relatives would support him.
From the information given its all hugs and condolences until the fostering conversation is mentioned then it's all suscipion.
Colin supported him in the early stages.
I have read Colins book, and even he was angry over some of the relatives behaviour, particularly the black flowers on shelias coffin.