4G

Was it a surprise that Hunting wasn’t Adam’s father? Any thought who it could be?

No, as he was an absent husband and father figure and Amy's mental state and her confessed affair supported the story line of another father of Adam.

Yes it was a surprise that Sturgeon was Adam's father from an affair that Amy had.

This revelation was somewhat of a surprise. At this juncture I was looking at Barry Castello as the likely father.

not really - he didn't seem to be much of a father or husband. Amy was already having affairs so it was just as likely that one of her lovers was Adam's father.