This is an excellent article, with a link below, but here is a significant quote from the article: (emphasis is mine)
Patrick Barnes, a pediatric neuroradiologist and one of the experts hired by Aspelin’s defense, explained how doctors now recognize “a variety of accidental and natural causes” that are sometimes overlooked in cases that are first diagnosed as shaken baby syndrome.
Barnes had testified for the prosecution in one of the most famous shaken baby syndrome cases — at the 1997 trial of English au pair Louise Woodward in Massachusetts. Since then he has come to believe that the syndrome is overdiagnosed and misdiagnosed.
You can read the article here.