That's all well and good, and the sign could have been there for all eternity - though in this case, it has no relevance due to the incident occuring on the other side of the road.
From brief reading of an article the other day, there seemed to be confusion or no firm knowledge if it was also...
The google maps image above was captured >2 years post-incident.
The sign may (or may not) have been put up afterwards.
There are further shared path signs along the road, and only on that one side of the road, most likely due to the pavement being wider than on the other side. Very standard...