Is it plagiarism if the material was previously published by a third party?

Is it plagiarism if the material was previously published by a third party (other than the claimant)? This scenario is of interest as a model for an assertion that involves the 1981 Nobel Prize in chemistry.

A survey was conducted on whether (a) there should be a statute of limitations on allegations of plagiarism and (b) an allegation of plagiarism should be deemed unfounded, unsubstantiated, or not proven when the alleged plagiarized ideas, processes, results, or words had been previously published in the scientific literature by an individual other than the alleged victim of the claimed plagiarism.

We received 287 complete responses. In all the survey questions but one, that dealing with statute of limitations on claims of plagiarism ("No"), a range of responses were obtained. About 40% of the respondents considered that unacknowledged communication of another's unoriginal ideas to be plagiarism, even when the content being alleged to have been plagiarized had been previously published by a third party and that the claimant acknowledged that they were aware of that previous disclosure by a third party.

Two major recommendations were made: education in RCR should be required for both students and faculty; and the evidentiary standard for establishing research misconduct should be increased.