It absolutely matters. Not only should the responsible party be held responsible, but it's indicative of the larger picture: the USA is more involved in the proxy war than they're letting on. They're killing peace talks, they're blowing up infrastructure as seen here, they had plans for Ukraine years ago that have started to come to fruition.

The only reason the USA isn't a first-party to this war is because there isn't deployment of USA troops directly in battle. There is still every other signifier of war participation: increased gathering and sharing of intelligence, shifting of money and allocation to the war effort, increased propaganda to shore up popular support, international negotiations to gather support from allies, use of USA's arms directly in battle, training soldiers (of other countries) for the war effort. Literally the only thing missing is USA soldiers on the front line.

Your comment reads as: "Russia is on the hook for something bad so who cares that the USA did something bad", which is nonsense.