We Helicopter guys should probably be a little less critical of Fixed wing drivers not recognising Vortex Ring. In most cases we get a hint of the approaching VR by a 'twitching' of the tail rotor. This is due to the recirculating air at the back end playing silly buggers with the T/R. I am assuming that the same tell tale would be non-existent in the V22. I understand that this is just one type of tell tale but from personal experience, it is one of the best hints that you are close to the edge.
I have a question for you guys. How is the V22 controled in the yawing axis? Is it by a differential vectoring of the pods? If NOT - could a boot full of opposite rudder help to correct a wing low situation. I am assuming of course that there is still at least some airflow over the wing.
One last point, another way to get out of Vortex Ring is to just lower the collective. This is great if you have altitude up your sleeve, but even so, I have found through experience that you can 'milk' the collective to disrupt the formation of a vortex.
The moral of my little story is that I don't think it is a design 'fault' either, and as in Helicopters there are ways to deal with the inherent problems that are associated with coming back to earth.
Cheers.