I think they're also asserting it on the basis that it's widely acknowledged to be a stronger design. However there was one engineer earlier in the thread who seemed to have some involvement with the Pendolinos who suggested that Grayrigg provided engineering evidence that their coaches were a step ahead of legacy coaches.
As I wrote in the 'Class 230' thread since 2008 all new designs have to meet the relevant requirements of the European standard EN 15227
Railway applications - Crashworthiness requirements for rail vehicles. Structural requirements for railway vehicle bodies are defined in EN 12663.
This means that currently manufactured stock for use in Europe (including the UK) is designed and tested to common standards which are applicable to new designs of:
- locomotives,
- driving vehicles operating in passenger and freight trains;
- passenger rail vehicles operating in passenger service such as trams, metros or mainline trains
While the Pendolino predates these standards by a few years the standards are based on the accumulated knowledge of the railway administrations and manufacturers across Europe so designs prepared in the decade or so before the EU made the standards mandatory will be very close to meeting them.
It is a truth universally acknowledged, as Jane Austen wrote in another context, that newer designs are better than older one in ensuring survival space for drivers, train crew and passengers in the event of an accident. But standards and specifications cannot cover every single set of circumstances so outcomes will remain to a large extent a matter of chance.
But it remains that not stopping quickly gives the best outcomes...