The point that the prosecution needs a line of argument is probably valid. Whether they pursue a line which is sensible is another matter.
My (limited) understanding was that they were originally talking about wget and Roxio, and by implication a CD Writer. If a sensible line of argument was to be pursued we might expect it to be complete - i.e. (i) did the defendant also use a piece of software (which happens to be well known and used outside of UNIX) to burn CDs, and (ii) did the defendant use CD-Writing hardware (which happens to be found on most notebook/desktop computers, i.e. used by an even larger chunk of the world’s population) to accomplish said task? If these points were not included in the line of argument, it is incomplete. What reasons would the prosecution have for mentioning only the least well-known utility involved in the alleged chain of activity? Is this show for the judge or the media/public?
(Caveat: I wasn’t at the trial either and haven’t read much recent coverage. These points may be addressed elsewhere for all I know. Also I’m not American … it’s just that someone may be wrong in a trial on the internet…)