Although the person knew about the rule, he or she decided that for some reason this was not applicable.
It does not have to be a bad thing, however there are some facts to check. "Situational violations" occur when there is a gap between what the rules or regulations require and what is available or possible - Lack of local resources and equipment or a lack of insight into local working conditions. This increases the pressure on people to break rules, to get the job done and achieve their goals.
However sometimes it is possible to get work done quicker and simpler, or just to get a kick, by not following the rules. This might be done to achieve perceived or real organizational goals (such as getting jobs done on time, or getting more income) or are a way to excel for the organization. Look what I am doing! It is much quicker this way! Bonusses focussed on performance, or unclear communication of the organizations goals can contribute to this type of violation. We believe that if this happens quite regularly, you would seriously have to look at your company's safety culture.