https://ottawacitizen.com/news/police-arson-unit-probes-otta...
"We don’t have any direct linkage between the occupation—the demonstrators—and that act." [1]
[1]https://www.cpac.ca/episode?id=fa5721d6-af8b-48d9-9848-73dcf...
What that likely means is that they don't know who the people in the video are. It seems pretty likely to me that it's related to the occupation, especially since there was a 'confrontation' earlier that day with residents of the building. It's not like buildings are burnt down in Ottawa every day.
No building was burnt down.
This is one of several accounts I use because my personal identity is tied to my main account, and accusations like the above concern me when I know there are vigilantes out there who find joy in doxing people with different political leanings than them. Rest assured I've been a member of this community since 2014, I'm not one of the dreaded "alt-right trolls" some users are so comically paranoid of.
On that note, I'm not really sure what's alt-right about repeating a quote from an investigating officer, but then again, most people who use that phrase aren't being intellectually honest anyway.