Here is a more complete quote of the gas issue from the article: “Including the already running, uber-ridiculous subplot that Russia blew up its own pipeline when Gazprom could simply have turned off the valves for good.
And once again, it gets worse: Gazprom is threatening to sue the Ukrainian energy company Naftofgaz for unpaid bills. That would lead to the end of Russian gas transiting Ukraine towards the EU.
As if all of that was not serious enough, Germany is contractually obligated to purchase at least 40 billion cubic meters of Russian gas a year until 2030. Just say no? They can’t: Gazprom is legally entitled to get paid even without shipping gas. That’s the spirit of a long-term contract. And it’s already happening: because of sanctions, Berlin does not get all the gas it needs but still needs to pay.”
So it basically comes down to international law and how this payment dispute will work out. First of all the contract language is critical. Proving as fact if Russia turned off the valves or blew up the pipeline weakens their case for payment, but proving the West blew up the pipeline strangthens their case. Providing at this point that International Law can even be practiced in the current context, which perhaps it cannot, especially if it gets a lot worse. Germany might never end up paying.
No, it isn't, and I've been practicing law for nearly three decades. Obviously, the specific language of a contract controls, but the article doesn't appear to be citing to specific language but only a general principle. The spirit of a long term contract requires both sides to be willing to perform. If Russia is offering gas, and Germany refuses to buy (as in sanctions), Germany is still liable. But if Russia is not offering to deliver gas, Germany doesn't have to pay.
Actually, the destruction of the pipeline would likely trigger what is usually referred to as an "impossibility" clause - very common in contracts - that would relieve Russia of the duty to deliver, and Germany of the ability to pay.
Obviously, all that doesn't consider issues of sovereignty and enforceability. There's no way in hell Germany is going to pay for gas it isn't receiving, regardless of Russian claims, so it's all moot anyway.