renaults are probably the safest cars on the road. no arguements, look at their ncap ratings.
as for the disco..... yes, it is 80's technology in everything up to a TD5 so why not compare it against a mk1 espace (big wedge on wheels) but i would still much rather be in a 5 star car given the choice and knowing i was gonna crash!
had that been head on, i feel the renault would have come off worse than it did there but the disco would have suffered even more too.
also, if sitting in the very back and shunted from behind - i would proabably rather be in the disco than sat with my head inches from the glass and a collision like i would in an espace (mother used to have a mk2 espace and i always sat in the boot....... very un-nerving when you stop at lights etc.)