Object on the road, maybe. Over the handlebars and all bets are off.
A small dog ran under my bike from the side once. Came out of tall grass and hit my chainwheel. I was around the 25 KMH (c. 15MPH), just rolling out down a small hill. Broke my collar bone, 4 ribs and shoulder blade. I remember telling myself to get my chin tucked, which is all I had time for. Have to give up other body parts to keep your head protected.
Have to figure on e-bikes nowadays, too. They're a plague where I am. Lots of old fucks who were never athletes and have no adequate speed/time/distance perception/coordination while they're body is in movement, IMO. Bad cycling habits, like side by side talking on bike trails around blind corners and then freeze when they see oncoming traffic Lots of accidents.
Don't know what it's like there with e-bikes.