"Court of Cassation" was the expression used in English language newspapers of 1992. The actual retrial was, admittedly, a publicity stunt. But it was based on proper research, some of it dating back to an earlier attempt at a retrial in the mid-1920s.

I defy anybody to read the translations of the trial documents thoroughly & not notice a) clear evidence of evidence extracted by torture & b) serious contradictions in the evidence. For instance (& noted by Georges Bataille, the most hostile of biographers) a string of missing children at Machecoul when Gilles was living at Tiffauges...