You knows the risks you takes your chances.
OH and the questions are flawed. Try asking how many hours of accident free/injury free cycling there have been and there will be huge numbers to be bandied about. Not saying it proves things one way or another.
The “what if” arguements don’t stand up to scrutiny unless you go back and recreate the accident without/with the lid in place and i personally am not willing to crash test dummy every scenario but i know some people who i would volunteer.
It’s the “this crash could have been nasty therefore every crash could be nasty” arguement.