It could be the case.
The question is, how to distinguish one who can get up to speed quickly from one who cannot.
In the end, there are expectations of the engineer, and expectations of the company. If the candidate is super-rusty, question is, why? For extended period of time this engineer did not code, and apparently was comfortable with it. Would such a person be happy in the environment, where 50% of the time goes to direct development (remaining 50% -- mentoring, project management, etc)? Note, I wrote development, not coding. But writing technical docs is not development either.