That could have ended badly for sure. There is a video floating around of a guy getting hit by a tire coming off a vehicle going the other direction, actually killed him, rotten luck.
I have had two instanced I can think of, one was a hubcap that came off the car in front and to my right, the cap crossed the road in front of me, hit the center divider, then came right at me, but fortunately I was able to avoid it. Not as dangerous as a garbage can but still capable of doing damage with all the force applied.
The other instance was when I ran over a piece of 2X4 that was laying directly on the painted line and almost invisible, I had turned my head to shoulder check, then started changing lanes and then saw it in front of my wheel, too late to avoid it I just ran over it with both wheels and luckily it didn't flip up and damage me or the bike.
One guy at work came around a corner in his car and there was a ladder laying directly across the road which he ran over, it tore out parts of his undercarriage and did other damage, on a bike that could be really ugly.
I remember seeing a car that had run over someone's bed mattress at speed, it had wrapped around his front wheel well and bent everything under there. The mattress had flipped off the top of a car in front of him, not tied down properly.
Best rule, never follow behind a truck as they may toss rocks at you, and never get behind someone carrying an odd load. I also change lanes if I cannot see in front of the vehicle in front of me whenever possible, like a bus, or van etc.
I wish they would outlaw blacked out back windows, Looks cool, but very dangerous to vehicles following, but that will never happen.