Not only was that law a rancid bit of obvious strike breaking designed to give make picket lines illegal, but I'm also pretty sure you'd have to have an almost metaphysical reading of it to actually apply here.
From what I remember at the time, the activists repeatedly disrupted the film shoots around London by chanting and making noise, until the sound people would call time on a location or the production beancounters would pull the plug on a location because it was costing too much money to have the whole crew sit around all day waiting for protestors to stop making noise and leave.
Now add in the fact that these shooting locations (the "workplace" that was apparently "restricted") were public spaces in the heart of a capital city that they activists lived in. Being gifted a shooting permit for public space in London doesn't entitle you to demand that no noise is made nearby by the people and the city that exist around it.
I've worked on shoots in major London train stations and if you'd asked anyone (management, the council, coppers, the public) for everyone to stop making announcements or talking on their phone or doing any one of a thousand other noisy things they would have (rightly) treated you like a crackpot. The production company didn't abandon these shoots because they couldn't continue, they did so because it was easier and cheaper to do so and just fucking green screen it like the rest.
This is lawsuit harassment almost certainly directed by the like of UK Lawyers for Israel being used in conjunction with extra-legal policing to criminalise peaceful activists, straight up.
I'm just imagining some runner straight out of college being made to unpack a Stinger from a wooden crate.