Ignorance of a matter of fact may in general be alleged in avoidance of the consequences of acts and agreements, but such ignorance cannot be pleaded where it is the duty of a person to know, or where, having the means of knowledge at his disposal, he wilfully or negligently fails to avail himself of it (see Contract).
Some of these errors are caused by the ride's operators, such as failing to ensure all restraints are closed and locked, negligently operating the ride, or allowing activities that are inappropriate in the ride area.