Hey Dave,
Dead right. So many of the injection parts are the same its not funny.
For people wondering, Diesel Injection achieves such high pressures by having such incredibly tight tolerances. It is possible to do this because of the lubrication that is contained within Diesel fuel > Petrol has no such lubrication.
So essentially what happens is more or less the same thing as when you run your engine without oil, everything picks-up and scores. The injection system lasts much longer than you would think under these circumstances because literally everything in them is made from a super hardened tool steal - so it takes quite a while for it to turn itself inside out. but it does happen.
Normally, even when its all gone wrong, its still possible for the motor to run, but not enough to start the car (ie build up injection pressure at super low - cranking - engine RPM). Hence this is the most common fault experienced when they come in on the back of a tow truck!
Hope this helps guys
Matt