files are added even after a 400 Bad Request with error "source uri format is not supported"

When I try to add some file and provide an invalid source-uri, tank replies with a 400 but nevertheless adds the file to the show.

Like here: Screenshot_from_2019-04-23_15-12-09

And here's the GET from this newly created show with the file just added: Screenshot_from_2019-04-23_15-12-19