Neither the article in the OP nor the Business Insider article claim that it was an attack by Ukraine. The BI article says that Ukraine hasn't commented on the explosion:
The Ukrainian military has not commented publicly on the explosive incident at the Russian facility. It frequently carries out long-range missile and drone attacks against Russia's energy and military facilities, including ammunition depots.
I'm not saying they didn't do it, or that the accident explanation isn't propaganda, just pointing out that OP mayhaps is pulling this out of their ass:
Apparently, Ukrainian drones pushed through and started a chain reaction.
So? Maybe there's a case against him for regular piracy, but streaming a game pre-release doesn't seem like anything remotely close to copyright infringement. If anything, it's journalism and protected speech.
If a leak causes damage to Nintendo's marketing plans, then Nintendo shouldn't have let it leak in the first place. That's negligence on their part.
Of course idk the full story here. Not showing up to court and handing Nintendo a default judgement is stupid.