I also read that article with a bit of alarm. I was hiking last year in Molise, in Italy and found some forest areas that were well disturbed. I confirmed with the ranger that it was the work of cinghiali, wild pigs. Didn't look to disastrous, though, sort of along the line of what turkeys and deer do around here looking for acorns, but a bit more extensive.
Wow. We probably need to enact rules to keep the pigs from going off-trail. It sounds like they're nearly as harmful to nature as orienteers.
It sounds as if what you saw could be likened to a few turkeys scratching at the leaves, hoping for an acorn or two, or perhaps a young doe nuzzling a fallen ripe apple.
That's not the right image.
Picture instead a powerful bulldozer armed with massive ripping teeth, and think of what the forest floor would look like after a few hours of determined assault. That would be closer.