Communication between workers, and workers and management is the key to workplace safety. Although the primary fault may lay with the maintenance worker's decision to engage in a potentially dangerous action without supervision, he might have been prevented from doing so, had he at least informed the other worker on the floor? And even if he had foolhardily gone ahead, at least the collision might have been prevented because the fellow worker would have desisted in his own authorized action to make way for the unauthorized action.
Ignorance of company safety policy and ignorance of multiple operations going on in the same workspace are the main factors leading to this multi-causal accident. It is easy to be safe in the best of circumstances, but one reason that UK statutory legislation specifies that proper safety protocols be followed, and dangerous actions such as the use of a crane to change...
Likewise, his immediate supervisor could be disciplined, as he had left the workers' parallel labors unattended during the collision and although the first worker had made no efforts to inform the manager of the exact nature and procedures of the work he was doing upon the day. But prevention rather than punishment is key. Rather than subject the man or the manager to disciplinary procedures, it would be better to have a company training session regarding workspace and place safety to avoid a recurrence of this type of accident.