He 'failed' to get the consent of hundreds of parents whose premature, vulnerable babies were put into his study into a new ventilator he had designed (which turned out to be a Very Bad Idea indeed and left babies brain damaged at best.). When the parents complained, he somehow managed to find a load of consent forms that he claimed contained the parents' signatures (they disagreed) but which were allegedly obtained by junior members of staff, not him, contrary to proper procedures.
It seems he had other children taken into care in order to use them as guinea pigs, or threatened their parents with care proceedings if they didn't consent.
And he certainly interpreted actions as abuse that had innocent explanations, as Kathy says. He's been found at fault by several investigations, at different levels such as the NHS regional offices.
Thing is, he probably did uncover some actual abuse, but his shoddy, over the top behaviour casts doubt on all his work. You can't believe what he says.
I think he was convinced that he was God, and that he saw abuse everywhere and believed he was standing alone against abusers. Meglomania.