Is there any evidence that an ejected car occupant injured a bystander even once?

If you're catapulted through your windshield, you're going to hit whatever you drove into, not traffic.

If you hit a giant wall, sure.

In the other case, a violent roll over accident will happily eject you from a side window and off on a happy trajectory towards whatever might be in that direction.

Forward through the windshield is hardly the only way to be ejected.

You're going to fall out in the direction you (and the car) are travelling/rolling.

You're going to be thrown out in some additive vector of where you were going and where the other car influenced your car to go, depending on what other impacts you're getting pre-ejection. That can easily be into another car, into other traffic, etc.

whatever you drove into could be traffic