The only path markings I saw was a STOP, a diamond and a bicycle direction marking - nothing that said "Bicycles Only". Diamond markings are intended to mean restricted use, but need to be coupled with signage as that symbol is used for a variety of vehicles. That bicycle direction marking is used everywhere on shared roads and paths - Seattle streets have them everywhere in lanes that are also for car use. And the video shows multiple entrances with no markings or signs.

There is no reason a casual observer would see those markings as being "no ped", and many of those people got on the path from this busy area at spots with no markings at all. If the city was looking to construct a dangerous place for cycling, this is it.