What the article shows is that there were people living in Otautau long before British settlers arrived in the 1860s. Of course this is obvious because there are so many Maori placenames around the area. Unfortunately there is no date to the story to gauge when these events occurred. But one reference I found stated the Ngai Tahu migration occurred around the mid-1600s. The regrettable fact of colonisation is that so much indigenous history is lost so it is a wonder that even a small story like this which happens to mention Otautau survives.
Another locality where there is said to have been a great fight is the western head of Te Waewae Bay. This point is now called Sandhill Point, but to the Maoris it was Hakapureirei, and here the white people found a large accumulation of human bones, with the result that tales of fierce slaughter are told of the spot.
The Maoris know of no fighting there, but tell the following story of the district. A Kai-Tahu chief named Hotu, some time after the fighting at Matauira, Preservation Inlet, made up a taua to visit there. Instead of going in canoes they went overland along the coast. When they got to Te-ahi-weka (now known as Price's—near the Big River) they spied a Kati-Mamoe man named Te Hiku-maiua or Te Hiku-maio high up on a cliff. Detaching men to surround him, Hotu shouted out questions at him, finally asking what were the names of the streams between One and where they were. The unsuspecting Kati-Mamoe began with Oreti, and had come as far west as Waitutu, when he heard a stick snap to one side of him. Like a flash he realised the trap and fled, just escaping his enemies. The taua went on to Rakituma (Preservation Inlet), but found no one there and returned. On the way back they cautiously approached Te-ahi-weka and saw Hiku-maio fishing on the rocks. They caught him this time and put him to death. Hotu settled down at Hakapureirei with his brother Tama-tahi-ora, and other families spread along the coast as far west as Waipukiu, near the Big River or Hakapoua. Discord crept in at Hakapureirei and Hotu killed his brother, and seized the latter's wife. Tama-tahi-ora had two children, but Hotu instead of killing them left them to starve while he cleared out with their mother.
The girl was of a fair size, and caught fish, which they dried in the sun and ate. Hotu had put the fire out before he left and the children had no means of making one. Taking her small brother the girl resolutely set out after the mother. They managed to cross the Waiau on a mokihi or raft, and after many wanderings eventually reached Otautau, where they told the people their story. Hotu was settled on the Aparima, and had told everyone that his brother and the children were dead. When they heard the children's version the people were highly indignant and a seer proceeded to makutu or bewitch him, and he died in consequence. It was after this that the people settled along the cost beyond the Waiau River in numbers, but how the bones came to be in such quantities at Hakapureirei the narrator could not say, but another native said that a great number of people died round there from the measles in the early whaling days, and he considered that was why the bones were