In reply to jon:
Look at it from the other side
They didn't realise it had been climbed - as you said you didn't publicise it.
The rest of the crag is bolted, so it was natural to assume it hadn't been climbed. Furthermore bolting, regardless of the oppurtunities for trad gear, is the norm in France.
These guys wanted the challenge of the line, clearly pretty tough, without the additional concerns of placing and trusting gear. Climbing for climbing's sake - not hard to relate to surely ?
And finally, not only would you require unusual gear (i've never heard of tube chocks), but you would require quite a few of them. Would it be worth the investment of well over 100 euros (at a guess) for gear you wouldn't need elsewhere
P.S. No amount of bolts would ever get me tempted to try a crack like that, neither in France nor at Curbar !!!