You can know which alleyway to run down. During a stampede? Even the 10-20 feet it would take to get to that alleyway can feel like 10-20 miles of getting elbowed, kicked, and stomped by panicking people.
Under a "normal" protest? When the tear gas starts flying, people pause to pull their mask up or wrap a scarf around their face. When the rubber bullets start flying? People take cover and suddenly you realize why that woman had a really heavy sign. Eothas forbid, a gunshot? You have people from The Hood who are tragically well trained in identifying what kind of gun that was and what direction it came from. And so forth.
When you have a bunch of shirtless dudes trying to pick up chicks and people focusing on the choreography for their protest dance? They haven't read up on what to do. They aren't listening to the hippie with a glass eye talking about what happened the last time the cops rushed them. When the tear gas starts flying? They get the fuck out no matter what it takes. Which turns a protest into Black Friday at a Toys R Us. Same with that car backfiring (or that dumbass having a negligent discharge...).
Newbies at a protest is good. We need more bodies. But you need newbies who actually "care". Rather than people who are just looking for an excuse to show off their gym bodies because they painted a message on their chest.
That said: I am REALLY happy that the frog suit protests in Portland have gotten so much (social) media coverage. It is pageantry but it is also REALLY effective PPE.
OTOH a massacre would likely destroy Republican legitimacy among a chunk of their supporters
A "stampede" where a protest turned on itself because of an inciting incident (false flag or not) just paints the victims as rabid dogs. It is an extension of "The LA Riots were full of looters" and so forth.
But also? I dislike how much people have decided their lives are Call of Duty and they are going to John McClane their way through The War. But I still think "Who are you?" from Andor is essential viewing for anyone who at all cares about the world. Because it depicts exactly how a false flag can be used to incite a powder keg and turn genocide into "both sides". And the follow up episode makes it 100% clear what happens when the fascists control the media that is reporting on what happened.