I do not quite understand the situation. It seems like some kind of test was conducted, that your friend was not a participant, nor even a witness of the test, and that the report somehow discusses the results of the test. Can you give any more information? What was tested? Why was it tested? What role, if any, did your friend have? To whom will the document be sent, and what will they do with it? What does the document itself say? I don't know if you know any of these things, but without knowing more, I cannot give you any assistance.
All I can say is that everything depends on exactly what it is that he is being asked to sign. I mean, whatever appears immediately above the signature line is what tells the world the reason for the signature, and the limits of its applicability. For example, there is a huge difference between signing the following two versions of a signature line:
Signature Version 1: I certify that the test was conducted as described, and that the results of the test were as described herein.
Signature Version 2: I am forwarding herewith a copy of the test results.
In version 1, the person signing is taking responsibility for everything related to the test. In version 2, the person is no more than a messenger, and is certifying nothing whatsoever about the test itself.
