I know exacly of the wall that you are talking about.
I used to get in shouting matches with that old guy, he even came up in my face and wanted to kick me off that wall, while there were 10 other people fishing there which he had no problem with.
Stayed there and fished and told him to call the cops if he had problem with me fishing there, he never did so I dont really know.
There is a little trail that goes right beside the wall and i didnt think it was a property of that park there.
I see people fishing there all the time.