Evacuation Day Van Arsdale drawing

Please help shed some light on the mystery of the linked Evacuation Day image. This seems to be the definitive picture of Patriot John Van Arsdale, who climbed the greased flag pole in Manhattan to replace the Union Jack of the defeated British army with the Stars and Stripes.
What bothers me about this image is the Union Jack has its colors reversed - It’s red background and blue stripes! Although this image is petty much always presented alongside a description of Van Arsdale’s feat, rarely is any note made of this. The one mention I did find suggested that this was the “Post-1791” Union Jack, which makes absolutely no sense to me and I haven’t been able to find any other image of this purported version of the flag. Moreover, as we know, the Union Jack is made of the three flags of the constituent three kingdoms, none of which having changed up the colors in the 18th century.
Does this mean the artist (who was he!?) just goofed? I find it hard to believe that nobody pointed it out to him at the time. Could it be he reversed the colors out of pure disdain for the Brits? Was this commonly done?
Please help! My googling skills are clearly not up to snuff.


Eh, he didn’t get the American flag right, either. There should be some stripes underneath the starfield, but there aren’t.

That said, might it have been a battlefield standard instead of the national flag?

At least the colors are right … I can see how he would take some artistic liberty to make the flag more pretty in the picture. The British one there is no logic.

Here’s a list of all conceivable British flags ever used, including battle standards. Nothing :-

It’s funny. I have never heard the name “van Arsdale” as far as I know. Not five minutes before finding this thread, I read it here, although referring to another guy.

I think it’s the reversed color post-1801 Union Flag, before they added the flag of St. Patrick to commemorate the “protecting” of Ireland and transition of GB>UK. Naturally, the evacuation occurred before 1801 (or 1791), so it’s anachronistic there.

The Wikipedia page for this image says that the “U.S. flag appears to have 12 stars in a circle surrounding a single central star; British flag shown is the post-1801 UK flag with blue and red reversed, not the pre-1801 GB flag.”

ETA: the Russian Naval Jack is similar, but not identical to, the reversed pre-1801 flag.