Flags and their history and design are a bit like gynecology . . . no, make that genealogy, in that once you start looking at it closely you wander off into all kinds of sidebars, back paths and sidetracks. Whoever saw in that a confederate flag did see that the confederate battle flag and the Red Ensign did have a common design element, the so called, St Andrews Cross, the diagonal bars. The Union Jack is a combination of the St Andrews Cross, which is associated with Scotland, and two other crosses, whose names I forget, associated with Ireland and the English Crown.
Anyway, it all gets very ethereal, like assembling a Coat of Arms and reminds me of Mark Twain’s mockery of coats of arms – cigars puissant on a field of argent serpentines, or something like that.