Remember, this is a nuclear armed state. Plausible deniability had never mattered to them. Sergey Lavrov will contradict himself in one sentence if need demand.

But as long as flags of convenience exist, sufficient unto the day, once, for each ships captain.

To cut one cable by accident would be a misfortune, but to cut two looks like carelessness as Oscar Wilde might say.

(The article talks about plausible deniability at great length. The point is that it suits the western powers not to have to read this as an act of war: they are the ones who need the plausiblility)