I don't know if the evidence is conclusive, but I do think we can say China is supplying Russia with military hardware and supporting them in other ways. So.. it's possible.
Reading that thread it sounds like it was a Russian ship that was sold to China last month (perhaps as a pretext to mask this) so ownership is unclear.
China trades with pretty much everybody, don't read too much into that.
China is not allied with Russia and China is unlikely to engage in sabotage like this because they stand nothing to gain from it.