Evil - is he tired when going down? Is he going into a cold bed? How much sleep does he have in the day? He's only 12 weeks, it's quite little. Ds at 10 weeks goes into him pram at night but has his dummy and my hand on his chest/hugging him gently. He goes off like this.
Our bedtime routine doesn't start till 9.30pm as before this he's not ready. At some point it will need to come forward but I'm hoping it just happens.
Is it worth looking at a later bed time?
I personally think letting them cry it out in their bed means they associate it with that. A bit like our experience of breast feeding!!