1998 Ford Contour Oil change

Engine Mechanical problem
1998 Ford Contour 6 cyl

My husband had our oil changed at a quick lube place. He drove straight home after, and the next day when he got in the car to go to work it started knocking. It had never knocked before. He was afraid the car had thrown a rod. We called the place and they came out, opened up the car, said it had oil in it so it wasn't their fault.

I didn't believe it -- just way too much coincidence. I think they ran it without oil in it, but we couldn't afford the $500 a mechanic wanted to drop the oil pan and see if he thought it was due to long-term lack of maintenance or a one time run without oil, so the car sat in our driveway for 6 months. Now that the weather is warm, my husband dropped the oil pan himself, looked inside, and found that the reason for the knock was one bearing was, in his words, burnt up -- completely disintegrated.

My question is, does it sound like something that would have happened from a mistake at the oil change place? I don't want to press the issue if it was just a coincidence, but WOW it doesn't seem like one to me.