Have I been scammed with this lens?

TLDR; I recently bought a Canon 24-70mm f/2.8L II lens in new condition from someone on Craigslist, but now the same person (verified by phone number) is listing yet another Canon 24-70mm f/2.8L II lens in new condition just two days later. What could be going on? Did I get scammed in any way?

Here are the relevant details:

I saw the lens for sale a few weeks ago, but I was too busy to meet up. Finally, I contacted the person last week. I wondered why the ad was just posted a day before my initial contact.

When I asked via text why they were selling the lens, the reply was that they were switching to Nikon. (Who switches from Canon to Nikon??? Just kiddin'.)

When I was making the face-to-face transaction, I was told through broken English that the lens was being sold since his wife thought it was too heavy and decided to switch to Sony. (I admit - it's possible that they were considering Nikon a week before.)

The original packaging and accessories (bag, hood) were all included. It also had a warranty card and box label with serial numbers matching that on the lens. The lens has no wear marks on the contacts and no signs of use, whatsoever. (I actually already have one of these lenses and am just getting a second one for stereo photography - at the zoom extents, of course.) I checked the zoom and focus rings for grittiness or slop, checked the aperture blades (using the exposure simulation button on the camera body), and ensured that the image quality and focus abilities were like that of my other lens.

I've been using Canon gear for only about 17 years but have a whole array of L lenses, so I *think* I've covered all my bases, but is there a good explanation why these people would have multiple "new" lenses for fairly cheap ($1150) that doesn't affect me in a negative way?

I suppose my only concern is that I can't get warranty service, but I think that's about it.
Thanks!