CV Axle boot fell off?

There's much more wrong than just the boot. Thank you for posting the dandy video. More likely, the boot was pulled off by the badly worn inner CV joint. That's what is allowing the shaft to wobble so badly. I'm guessing the person who inspected the shaft didn't run it in gear like you did, as the wobble would have been evident.

The good news is rebuilt, and even brand new half shafts have come down in price a lot. I needed a new shaft for my '88 Grand Caravan a few years ago. The boot repair kit was over $35.00, and is a messy job. A brand new shaft with additional ABS system parts so it would work on newer models, was only $65.00. 20 minutes and I was back on the road.

Check at your local auto parts stores. I suspect you'll find it doesn't even pay to look at a salvage yard.

Let me know if you get this solved.