Q: Loss of brake pressure, CV shaft popped out. What might have happened, and where do I go from here?

I recently had a wheel bearing job done at a local shop to the front driver side of my Camry. During the repairs, the mechanic stated that the CV shaft and ABS sensor became damaged during removal and needed replacement. I got another call saying the new wheel bearing had exploded inside the knuckle when it was on the press, it needed to stay another day. Finally I picked it up. I noticed when I put it in drive, my brake pedal went all the way to the floor, and there was a grind from the transmission. I drove it home with no brake pressure (I live a few blocks away) and every time I accelerated, it would grind. I pulled into my driveway, using the hand brake to stop. I switched to reverse to turn around, and heard a loud clunk from the car, then it wouldn't move at all, now followed by a constant grinding when in gear. I crawled under to see the CV had disconnected from the transmission. It now rolls freely in park. They say they don't know what happened. I'm not losing brake fluid.

My car has 169000 miles.
My car has an automatic transmission.