Anglo-Saxon legal customary law

Leslie Bergh and his two brothers, Milton and Raymond, formed a partnership to help build a fancy saloon anddance hall in Evanston, Wyoming. Later, Leslie met with his friend and drinking buddy, John Mills, and trickedMills into investing in the saloon. Leslie did not tell Mills that no one else was investing cash or that the entireenterprise was already bankrupt. Mills mortgaged his home, invested $150,000 in the saloon—and lost everypenny of it. Mills sued all three partners for fraud. Milton and Raymond defended on the grounds that they didnot commit the fraud; only Leslie did. The defendants lost. Was that fair? By holding them liable, what generalidea did the court rely on? What Anglo-Saxon legal custom did the ruling resemble?