By the way, on mine I have had no knocking. The only time I ever had is when the ball joint failed on the drivers side wishbone. I replaced the balljoint without replacing the wishbone and have therefore never tampered with the offending bolt. The edge of the hole on mine doesn't look neat because its dirty, its not burred up as the picture might suggest. And I would expect at least some wear on the bolt shaft if its displaced 1.5mm of metal around the whole of the perimeter. The Renault explanation 'seems' plausible, just so long as everyones bolts are correctly torqued, which would explain the washer fix (bolts removed and re-fitted therefore re-tightened) On the other hand, being cynical, they could just be fobbing you off!
The thing is, it took Renault 7 attempts to fix my leaking headlight washer jet and that was with help from their 'technical department' they are such a big company that its even trouble for them to get info. The only way to be sure is if somone could confirm from the original drawings, which is highly unlikely to ever happen