Unsafe behaviour can take many forms. From simple failure to wear or use personal protective equipment (PPE) to intentional actions - such as the removal of machinery guards or defeating a safety mechansim. There a many reasons for such behaviour - ignorance, malice. The best way to find out is to ask why somebody is doing their job that way.

It may be something in the process that makes following safety procedures difficult or uncomfortable. eg many farmworkers do not like to wear PPE on hot days. It may be standard procedure - but wrong, practice that nobody has checked for years

Or perhaps the person has not got the necessary skills, as they have not been taught properly. eg lifting skills and advice have changed in recent years. Do you know? Stirling work

Any examination needs to identify the difference between errors, which are unintentional caused by lack of knowledge and skills, and violations which are deliberate actions. These should all be examined in the process of involvement and cooperation rather than blame.