I admit I didn't watch more than the intro. to the video. But curious about your recommendation--I know I don't usually like to waste time on what you recommend, I'll fully admit to that unashamedly after wasting too much time over the years with what you recommend an arguing about it to no good effect except debate games--but this one was new. So I saw the name "Bellingcat". I had a window open on NYTimes, I typed it in there and got this recent fairly lengthy article on Bellingcat and their rep and their work, mostly quite positive and even complimentary, including this excerpt late in the article on Douma:

[...] Open-source journalism has the same vulnerabilities as traditional journalism. A biased reporter or a reliance on sources with an agenda can lead to skewed stories. Some journalists and activists hostile to what they characterize as Bellingcat’s pro-Western narratives have criticized some of its coverage of the war in Syria.

At issue is an April 7, 2018, attack on Douma, Syria. Bellingcat reported, based on an analysis of six open-source videos, that it was “highly likely” that Douma civilians had died because of chemical weapons. In March, the Organization for the Prohibition of Chemical Weapons reported that there were “reasonable grounds” to say that chemical weapons had been used in the attack.

Critics of Bellingcat have pointed to an email from an investigator with the organization, saying that it raised questions about the findings. WikiLeaks published the email on Nov. 23. In a response, Bellingcat defended its reporting, saying the final report on Douma from the Organization for the Prohibition of Chemical Weapons reflected the concerns of the investigator whose email was published by WikiLeaks [....]

from These Reporters Rely on Public Data, Rather Than Secret Sources by Marc Tracey, Dec. 1, 2019