I think it was filmed long before any of the events of last summer. Also, I don't think they were really aiming for a police brutality vibe with that one. It felt more like a Black Mirror-y, dystopian future they were working towards. Whereas they have nods to current events in other ones (Brexit has had a few), I don't think anything in that one was meant to be much of a comment on any real world event. Like most episodes from this era of the programme, it felt like they were trying to cram too many themes into one episode, leaving none of them adequately covered.