"Reportable dangerous occurrences (near misses
If something happens which does not result in a reportable injury, but which clearly could have done, then it may be
a dangerous occurrence which must be reported immediately"
The 'something that happened' was that live conductors were left exposed and unguarded and with other people working in the area and for all 'we' know someone may have come close to getting an electric shock which could have resulted in a 'reportable injury'.
These are decisions for those on site of course because for example the exposure could equally have been in a place which by default was not easily accessable and thus it was then very unlikely that anyone else, other than the engineer doing the work, would have come close to the live conductors.
'Near misses' are generally a difficult one because in many cases one persons 'near' is another persons 'not so near'.