Sounds fishy to me..
All though that's just based on several experiences..
1. Ford Orion, PAS belt snapped, steering went so heavy it felt like I couldn't steer, but you could, just mammoth effort required.
2. VX Astra, switched ignition off accidentally when going along - Steering went mentally heavy again (Electric assistance), but was driveable.
3. Citreon C4 hire car - completely died when going up the motorway, no electrics, no anything, steering was again very heavy but it would turn, or I'd have died, as I was doing 80 and straight ahead was a corner with no barriers just a big ass ditch..
Granted in the Orion, I found it very hard to turn, and I was a Gym 5 days a wekk veteran at the time.. if I was not so strong, I'd have really struggled, it did nearly cause an accident, as I went to turn a corner, and nothing, just panic made me give it a huge effort, and it did turn..
Update: we've just tried my mates saxo VTS, engine off, ignition on, and with some effort we can turn it on the spot...