Task: Question Answering
Input (English): Passage: The Avenue Range Station massacre was the murder of a group of Aboriginal Australians by white settlers during the Australian frontier wars. It occurred in about September 1848 at Avenue Range, a sheep station in the southeast of the Colony of South Australia.
Information is scarce about the basic facts of the massacre, including the exact date and number of victims. A contemporary account of the massacre listed nine victims – three women, two teenage girls, three infants, and an "old man blind and infirm". Another account published by Christina Smith in 1880 gave the number of victims as eleven, and specified that they belonged to the Tanganekald people. Pastoralist James Brown and his overseer, a man named Eastwood, were suspected of committing the murders in retaliation for attacks on Brown's sheep.
In January 1849, reports of the massacre reached Matthew Moorhouse, the Protector of Aborigines. He visited the district to investigate the claims, and based on his enquiries Brown was charged with the murders in March 1849. Proceedings against Brown began in June 1849 and continued in the Supreme Court of South Australia for several months, but were eventually abandoned. Some key witnesses, including Eastwood, either fled the colony or refused to cooperate with the investigation. There were also significant restrictions on the use of evidence given by Aboriginal witnesses, especially where a verdict could involve capital punishment. These legal hurdles and settler solidarity ensured the case did not go to trial, although the magistrate who committed him for trial told a friend that there was "little question of the butchery or the butcher".
Although the details of the case were known for decades after the murders, distortions of the massacre eventually appeared in print and were embellished by local white and Aboriginal historians. Two key aspects of these later accounts were that Brown poisoned rather than shot the victims, and that he had undertaken an epic horse ride to Adelaide to establish an alibi. Historians Robert Foster, Rick Hosking and Amanda Nettelbeck contend that these "pioneer legend" alterations downplayed the seriousness of the crime. 
Question: What were the last names of the historians who contend that these "pioneer legend" alterations downplayed the seriousness of the crime?
Output (English): Foster.