Some en banc opinions are hard. Some en banc opinions are easy.
Today's opinion is an example of the latter.
The panel felt itself bound by circuit precedent. The en banc court, by contrast, was under no such constraint. So, based on intervening precedent by the Supreme Court, it overruled that prior circuit authority.
The en banc court was unanimous. The opinion was per curiam. The en banc court didn't even need oral argument. And getting the opinion out took less than a month.
Everything else goes back to the original panel.