The title is misleading and hyperbolic. The events were certainly not shocking. But they were disturbing and somewhat damning of the local police force and of the behavior of the men and women at the march.
The journalist, a woman, followed by a cameraman and filming with her own phone as well, spoke to several people, including Quebec politician Manon Masse, who is a 'cis' lesbian (according to their own claims. To be honest, I suspect this individual is hiding the fact that they are a trans-identified male BUT I could be wrong) and leader of a major Quebec political party.
The interviewees share their thoughts, including the opinion that puberty blockers are safe and reversible and were initially developed to treat precocious puberty in children (in fact, at least one puberty blockers, Lupron, was initially approved for use in treating prostate cancer in the 1980s. Throughout the years it's been used off-label to prevent precocious puberty in very young children (3 yr olds for example) and also chemical castration. However, it has had so many side effects that some people who took the drug seriously question its safety).
At some point, two young women wearing medical masks approach the journalist and ask her which media she's representing, which she refuses to disclose. This is where most of the trouble starts. The way that they ask the journalist is, in my opinion, meant to make her feel subtly afraid and cowed by authority and get her to submit to them. She is under no obligation to disclose anything, but I believe they want her to forget that and feel she does need to disclose it and treat them as legal authorities and treat what they say as law. I believe these two masked women understood full well they have no authority, and cannot compel the journalist to do anything, and are trying to use subtle and covert threat and assert dominance in such a way that they can claim ignorance if their intentions are openly named.
The above paragraph essentially represents how the rest of the journalist's stay went. The two women escalate their behavior and follow her through the park (the march hasn't started yet, people are mostly gathering and celebrating), repeatedly trying to apply subtle pressure and intimidation while being able to feign innocence. They keep asking the journalist which media she's with. She doesn't answer and asks why they need to know and if she is obligated to tell them. They try to manipulate her and use more verbal deception and misdirection. She catches them, during one of her interviews, off-screen giving a 'neck cutting' sign to the people being interviewed. At this point the journalist can't find more people to interview. Many have probably been warned that she is 'unsafe' and probably don't wish to be interviewed anymore. However, I also wonder if some of march participants are meant to be subtly threatened against interacting with the journalist in, again, a covert way that can be plausibly denied. She asks them why they're harassing and following her. They deny they are harassing her. They start asking her to leave. She points out they are not an authority and they admit they are not and keep simply asking her ('asking' while subtly but clearly threatening) her to leave.
At a certain point she speaks to the police. They do nothing but tell her to leave because she's causing problems. She explains she has a right to be there and that they should protect her. The police say there is nothing they can legally do. They make it very clear that they do not intend to protect her and are more concerned with using covert threats to get her to leave. I believe one says something like, "if you don't leave that's on you" or something like that.