I disagree. I think that it couldn't have been prevented. Well, not by social services at least. The social worker visited two days later again, reported to police and got hold of a key from the landlord.
The biggest thing that would have prevented this tragedy is 1/if the mother who seemed incapable of looking after the poor child, hadn't had a baby and particularly not with an I'll man in his 60s. But more than that, if she'd actually seen her baby in that two weeks or alerted police if she couldn't access her child.
It's heartbreaking and very easy to think that it could have been prevented, if only someone knew and had broken in immediately. However, social services often find that people are out when they visit. People tend to be away even more over the Xmas period. They can't break into every house. And, whilst one might question whether the baby should have been in the care of his father as he was unwell, equally, does the state really have a right to take children away from parents if they have health conditions? They were monitoring the situation weekly, which seems like an appropriate response to me. I feel for the poor social worker. They are almost certainly a caring individual, doing their job and now being scrutinized in the national press, having discovered a poor baby that died under their care. That must be horrendous for them too.