Very sad day.
Information is a bit ambiguous. One really needs a reconstruction drawing of where all the participants were at the time of the accident.
It looks like the road has decent shoulders. This is one of the reasons that I advocate riding on the shoulders. Less swerving necessary to squeeze past.
Of course, it doesn't help that both vehicles were large cars, Mercedes & Caddy, taking up more space on the road.
Also note, those wearing seatbelts fared better than those without.
The Caddy could have more or less safely swerved off the road and avoided the collision. But, everything happens quickly.