There's no doubting Volvo are still the trend setters for car safety but there always will be no rules when it comes to crashes, nothing can be taken for granted, and in this example the age of the cars will also have been something to do with it.
Have a look at this, though most will have seen it already:
https://www.youtube.com/watch?v=emtLLvXrrFs
And some more very useful consumer testing :-)
https://www.youtube.com/watch?v=dY91fZ--Tao