Here is the link to the study itself

First when reading the overview it is clear that the study is biased. It starts with, among other things, "...police killings continue unabated, at 2.5 times the rate for Black men as for white men" stated factually.

Next let's look at their methods. Its per geographic region rather than per protest. They identified 2,440 regions that had a protest and 220 were violent. So exactly equal weight is given to a small 50 person protest in Idaho that took place in the afternoon as 100 days of rioting in Portland. It's incredibly misleading.

The study blames the perception of violence on a misinformation campaign by the media. It ignores the fact that the violence is clear to any observer and appears at most rallies.

Next they blame the police for intervening in 9% of protests. You'll note here that they rely on the total number of protests rather than geographical area in order to make the police response seem disproportionate to their misleading figure. They continue this flawed reasoning by assuming that federal agents in Oregon caused the protests to become riots rather than the federal agents responding to the riots.

Ill read this in more detail and edit it as I find new stuff of it anyone points out something I missed.