You did well on that to be sure, but as learned from McCoy and Vaughn, it ain't as simple as A-B-C. Too often when graphics are presented to illustrate a particular factoid, there be more there for the taking if one has a broad understanding. Too many shooters are not educated on many of these issues and thus leap to erroneous conclusions.
One of the photos you posted illustrated the oddities as well as anything. It was indicated to be subsonic, yet had the shock wave...on the base, and not the nose. One of those "Oh no, Mr. Bill!" moments to some I suppose.
Just lending a helping hand as it were.