For those interested in what the gp could be referring to: There is a Wikipedia article and other sources on the "not proven" verdict of Scottish juries which w

For those interested in what the gp could be referring to: There is a Wikipedia article and other sources on the "not proven" verdict of Scottish juries which was/is in practice an acquittal. It's apparently still used in roughly 1/3rd of cases. There is a list of significant cases for which the verdict was used, though none seem to be related to political protest.