Heading into the final selection regatta in Hyeres, France in April, Winther said she had no idea what standard she needed to reach at the event to secure an Olympic nomination.
The Sports Tribunal described this lack of communication as "troubling".
"While the selection policy is drafted to provide huge discretion to YNZ, this does not obviate its obligations to abide by the rules of natural justice and to ensure basic fairness in its implementation. In particular, athletes in contention for nomination should be aware of what information they are being judged by and be given a reasonable opportunity to provide feedback on this," Sir Bruce wrote.
"I am not sure the athletes were given this opportunity or that the individual circumstances of the athletes in question and how they would perform at the Rio Olympics venue were adequately assessed in arriving at their decisions."
The Sports Tribunal considered whether to set aside the decisions and require the selectors to comprehensively assess the personal circumstances of each sailor in more detail.
However, Sir Bruce said having carefully weighed all the information presented, he concluded that realistically this would not lead to a different outcome.
Sir Bruce also rejected the argument put forward by Aaron Lloyd, who represented the two sailors, that the nomination decisions were affected by either apparent or actual bias. He said there was no evidence to suggest the selectors were incapable of making a independent and objective decision.
"Considering all the information now available I concluded there was a clear and adequate foundation for the selectors' decision."