Musk has said that his idea of the hyperloop involves a system that "can never crash". Assuming that he's not just talking about really robust safety protocols and instead is referring to some inherent property of the system I think there's probably some missing detail here.
Although I think overall this is probably pretty close.
I believe it will be encapsulated like a dedicated guideway train with walls on both sides so that a de-rail is impossible. The failure mode would likely be the craft slowing down and landing on the track if power is lost.
As a result the vehicle can never crash, but simply lands on the track as it slows down.
I believe Elon is referring to aircraft failure modes when he says "crash", as his Hyperloop vehicle won't drop from an altitude high enough to ever hurt the vehicle or passengers.
EDIT - Response to InclinedPlane's comment below:
The vehicle's angle of attack will be kept almost constant with aerodynamic control systems, similar to a rocket. The reason why NASCAR and F1 cars have spectacular lift crashes is because they are not allowed to have active control surfaces, allowing small aerodynamic perturbations to evolve into massive ones.
The vehicle will likely be kept a few meters off the track to allow for these perturbations. Since the angle of attack is controlled, the only way the lifting body can stall is if it is suddenly immersed in a continuous stream of fully turbulent air. Although extremely unlikely, this is possible, so it can be mitigated with an encapsulated tunnel with fans blowing air in from the outside to gaurantee consistent laminar flow, similar to a wind tunnel.
Maybe, but I'm not convinced. It doesn't matter if you're flying or not, if you're traveling at supersonic speeds and you run into anything, even if you hit the ground from a height of 10cm, it's going to be a bad time. Also, if you're traveling that fast it is magnificently easy to gain a dangerous amount of altitude quickly just by having your vehicle rotate and hit a favorable angle of attack. Just look at how dangerous and dramatic crashes in formula 1 or nascar are, and those vehicles are on the ground, and traveling at maybe 1/5th as fast as a hyperloop vehicle would (and with 1/25th as much kinetic energy).
I'm convinced there either must be some other factor at play or Musk must have worded his statements stronger than is warranted.
Exactly my bet, also if the rail is a tube he gains a way to store electricity in a kind of condenser, has an easy way to keep the "train" stabilized and also isolates the sonic shock from braking half the windows between L.A. And SF. Of course on top of the tube it's easy to install some solar panels.
Although I think overall this is probably pretty close.