A few days ago I posted Google Maps street view captures of the house at the end of Rue de Saint Real which is one of the cross streets that runs down to the waterfront park. That house has a security camera visible and the house is located only about 20m from the park, 40m from the path and 60m from the water. The park is very narrow at this point and because of the season (no leaf coverage), I would say that this house's security footage would give clear views right through to the water's edge. I am only suggesting that this could be the source of LE's video but it does check many of the boxes that have been reported.
shows location of house with camera with road end drawn in to match reality
google earth street view image showing house with camera
google earth image showing house with camera and proximity to park, path and river.