Well, it would depend on the size of the "fairly good-sized package", no?
Let us put the likely case: Mr Shelley saw a fairly good-sized package of the same size as that described by Mr Buell Wesley Frazier, i.e. one not large enough to hold a rifle.
Would his volunteering of this information be apt to be met by the 'investigating' authorities with
a) calm appreciation towards Mr Shelley for having helped them with their investigation?
b) panic?
Answers on a postcard, please! 
So! Mr Jack Dougherty tells the WC that "some of the fellows", including Mr Bill Shelley, spoke of seeing Mr Oswald with a "fairly good-sized package" that morning. Mr Ball must be
electrified to hear these glad tidings, for they promise to undermine the reliability of Mr Buell Wesley Frazier and Ms Linnie Mae Randle's description of a package too small to contain a rifle. Breakthrough!
There is only one thing for it: recall Mr Shelley for a follow-up deposition (he appeared before Mr Ball only yesterday) and ask him about the fairly good-sized package.
But Mr Ball doesn't do this. In fact, no effort whatsoever is made to follow this extremely important matter up. Why not?
Because the last thing Mr Ball & Co. want established on the record is that the fairly good-sized package seen by Mr Shelley & Co. was not nearly good-sized enough.
The WC knew full well that Mr Oswald brought a paper bag containing two curtain rods to work that morning, and that this same pair of curtain rods was discovered somewhere in the Depository after the assassination-------------and anxiously tested for Mr Oswald's prints. Their shenanigans in the Paine garage on 23 March proves it.
