Well, no; AIUI part of the problem was precisely that this update was pushed in such a way that it skipped any canary system in place. There might be a separate conversation to question what percentage of their users were taking advantage of its staged rollout features, but it's rather immaterial when the incident in question bypassed them even if users had configured it sensibly.
It depends on if/how it was communicated. If there's a big red box in the user manual that says, "this software might take updates that completely bypass any phased rollout you configure", then yes it was probably irresponsible to use it. If, however, the software lets you configure phased rollouts and fails to mention that they might just get ignored, then I don't see how the customer can be blamed at all. (And in both cases, if CS shipped such an update with exactly zero testing whatsoever, which strains credulity but is what I've read, then they still get most of the blame.)