This ones got the brain ticking.
Perhaps he is talking about the massacre and or genocide of Tasmanian Aboriginals. Who he is referring to and to what he was inferring that, that person had incited, leads me to say Henry Melville.
Melville was arrested by Arthur for inciting reprisals against the aboriginals by printing libellous stories about them which led to the killing of many. He was the editor of a newspaper in Hobart.