Why would that be the case? Ukraine has a very large IT sector and they have a lot of good IT security specialists. To be honest, a lot of cybercriminals have been from Ukraine.
So I don't see why it would be the case that Ukraine could not have done this by themselves. They have done previous attacks by themselves. I don't see why that would be the case.
It would kind of be like saying, "Oh, if Russia does a cyberattack, it can't have been them acting alone. It must have been China that gave them the stuff to just press a button."
It's the usual westerner superiority speaking. When Ukraine wins something it's always due to NATO training, US weapons and all that. When Ukraine starts losing ground it's poor soviet-era training, wrong kind of tactics and decision making on Ukraine.
That very article mentions that on a number of occasions Ukraine has gained intelligence or pulled off their own ops which the US was completely unaware of.
Just because they're being helped doesn't mean that literally everything they do can be appropriated to the US.
It's tough to say that Ukraine and US are allies right now. US refuses to hold security assurance, as promised, and forbids Ukraine to restore nuclear arsenal, as before the promise. Bullies behave is such way, not allies.
It is irrelevant to my interpretation of the aforementioned parent comment.
The point is that US made Ukraine do something that the US wanted to do but did not do because were it the US, then it would have had repercussions on US, so they made Ukraine do their dirty work.
So I don't see why it would be the case that Ukraine could not have done this by themselves. They have done previous attacks by themselves. I don't see why that would be the case.
It would kind of be like saying, "Oh, if Russia does a cyberattack, it can't have been them acting alone. It must have been China that gave them the stuff to just press a button."