Just one personal anecdote. Someone close to me in my circle, VERY responsible etc, was driving (under 30 mph, in an SUV) when a drunk homeless person just stepped right out into the road. They've been plagued by their involvement for over a year and it's affected their health similar to when a person commits suicide by throwing themselves in front of a train.
It bothers me when the phrasing is "Killed by Drivers".
That truly sucks for your friend. But the phrasing isn't inaccurate, and the source of their trauma is probably that they were responsible for operating the machine that killed someone regardless of their intent or caution, and not the phrasing of around it. They are well aware that they, as a driver, killed someone.
Traffic safety advocates have fought hard for reporters to avoid the passive voice, or using phrasing that avoids the involvement of the driver. Too many people were reported as 'having died in a traffic accident' or have been 'hit by a car'.
It probably bothers the family and friends of dead pedestrians when reckless drivers are reported to have been in an 'accident', or that their car killed someone and not the driver.
Had something similar happen to me before. Was driving down a main street that went through the edge of a college campus. A student on the side of the road, not at an intersection, decided to cross the road not too far in front of me.
It didn't even make sense to cross there, as I had just barely driven under a walkway that crossed above the street specifically for students to cross that street safely too. (I attended that college too. The walkway is more convenient than what they did). Surprised the hell out of me.
I had just barely enough time to realize what was going on and swerve around him. If my reaction time was just slightly less or I did the wrong thing in the moment I would have hit him head-on and either severely injured or killed him. I believe the speed limit was 35mph there, so I was likely going just over that.
That was like 15 years ago at this point, and it still bothers me how close I came to hitting him. I can only imagine how much worse it is for your friend.
It bothers me when the phrasing is "Killed by Drivers".