That's probably what the jury will be thinking as well. It plants a seed in the minds of people that this conversation might have occurred, which might be all the prosecution wanted to do anyway but without this person saying it himself who really knows?
Yeah, the prosecutors better keep their minds tuned to the "down to earth" side that most juries have.
I trust Brocchini's judgment that there was probably nothing in the guy's account of this "body disposal" discussion.
BUT, the jury does not always agree with the lawyers and witnesses as to what is significant, and THEY have the last word on what is significant! I can just see them coming back, after an adverse verdict, and saying, "We wish we could've gotten a chance to judge that college friend's tip for ourselves."