I suspect Scott Manley doesn't have better access to sources than we do. All he can do is interpret what he sees using his knowledge of the field.
In cases like this, it's tempting to gather any news you can, but everyone is laboring under the same lack of information. When an accident happens, there's only one source you can trust: the official accident report. This takes a while to come out, so until then everyone including Scott Manley speculates wildly based on incomplete information.
So when you see something that raises a question, your first step should be to find a primary source.
In this case, one item (buckling) is correct, the second (sparks) is questionable. From the accident update provided by SpaceX:
Specifically, the investigation team concluded the failure was likely due to the accumulation of oxygen between the COPV liner and overwrap in a void or a buckle in the liner, leading to ignition and the subsequent failure of the COPV.
So they mention ignition, but don't talk about a spark.
So why would Scott Manley say that? He's making an assumption. Not an unreasonable one: ignition usually implies a spark. But there are substances sensitive enough that you don't need a spark to ignite them: friction or impact loads are enough. Liquid oxygen + carbon is one such substance.
Using your knowledge of a field to explain an accident is another one of those temptations. I just did the same in the previous paragraph. Did I get it right? I don't know. I've gathered some evidence that supports my theory, but like Scott Manley I'm an outsider. I'm also not a physicist or chemist, and least of all an expert in LOX-carbon fibre applications. It's entirely conceivable I missed something. This is why primary sources are so important: everybody else has incomplete information.