Does error of judgment constitute negligence?

Wilson v. Swanson makes it clear, at p. 812, that an error of judgment does not necessarily constitute negligence: An error in judgement has long been distinguished from an act of unskilfulness or carelessness or due to lack of knowledge. Although universally-accepted procedures must be observed, they furnish little or no assistance in resolving such a predicament as faced the surgeon here. In such a situation a decision must be made without delay based on limited known and unknown factors; and the honest and intelligent exercise of judgement has long been recognized as satisfying the professional obligation. V. The Parties’ Positions (i) The Defendant