What if Bar-Abbas is not a parody, but a real marcionite thing

[Giuseppe]

Pilate would have freed the true Son of Father, while only the his mere appearance - the Jesus called Christ - would be crucified.

Apart the fact that this doesn't explain (differently from the Couchoud's hypothesis) the excessive moral denigration of Barabbas as anti-Roman killer, there is a little thing explained under this hypothesis: the legend of the fugitive Pilate, after the his conversion to Christianity.

That legend could be invented against Marcion insofar it is not Jesus the real fugitive, thanks to Pilate, but Pilate himself. To exorcize the disturbing voices about Jesus the true fugitive from Pilate. A Pilate fugitive towards Jesus was invented.