I have worked with the victims of child sexual abuse my whole adult life and I personally found the two men very, very credible. Everything about their stories; the things Jackson said to them, the gradual escalation in sexual contact starting with masturbation, his use of pornography as a way to normalise what he was doing, the way the boys were replaced when they got too old, the struggle to reconcile the feelings of love and affection they felt for their abuser with what he did to them...it's all so familiar. I've spent years listening to similar stories.
Those saying that Jimmy was too "emotionless", that's an accusation that is often levelled at victims of sexual abuse. They often appear very detached, almost cold, when describing their abuse. It's a self-preservation thing. Survivors will sometimes describe how they "left their body" while the abuse was taking place, as if they were watching it happen to someone else. If they allowed themselves to feel the full horror of what happend to them (the shame, the confusion, the revulsion, the physical discomfort, the guilt because they found themselves having an involuntary response of arousal) how would they actually go about their daily lives and function? How would they keep the secret, present as 'normal' in front of their families? They have to "detach" themselves to an extent in order to survive. As for Jimmy keeping the jewellery even though he found it distressing to look at, again it's not at all uncommon. It's a kind of self-punishment. The child is made to believe that by accepting gifts or money they are culpable and they blame themselves.
I think it's interesting that sexual abuse is the only crime where the default position is to be suspicious of the accuser, to scrutinise every aspect of their demeanour and make judgements about whether it fits with how we think a "victim" should behave. It's hardly surprising that so few come forward. No wonder these men lied, not just to protect their abuser, but also to protect themselves and their families from the inevitable backlash, from the intense scrutiny, from being labelled either as victims or as money grabbing opportunists.
He did it. There will be others. Anyone who believes otherwise is kidding themselves.