what penalty for wrong RADAR listing  

Human error
Maybe they have information which says otherwise or they have been wrongly informed by others and choose to take there ID, the mid century world is awash with wrongly attributed pieces.
I think your first port of call should have been a PRIVATE email to P&A and not a public one singling out a dealer who is aiding the site and one of P&As clients!
The practice of one dealer going against another dealer in thismanner always makes me cringe so please excuse if my response is not helpful or what you expected.

Editing and backtracking... I think I know the piece you are talking about Simon, but Arthur has made a very good point, I am sure we have all made mistaken attributions in the past with only the very best of intentions.
The dealer should be given time to amend the mistake.

Simon,
As everyone knows...
Simon,
As everyone knows on this forum, you are certainly one of the best international expert for Danish design, if not the best.
What is easy for you to spot, is not necessarily easy for everyone. Remember, we have to manage listings for Scandinavian, American, Italian, French, German, British, Belgian, Japanese items ... and our knowledge is better for some countries than for others.
For the last three days we had to validate more than 150 listings and we are overwhelmed with work. So it is possible that we have missed an error.
Contrary to most other marketplaces, we check and, believe us, we very often correct the listings. But obviously, we are not infallible.
Design Addict's strength has always been the collective knowledge of our community. Therefore, if one of you sees an error in an attribution, please kindly inform us (by email!). We always inform sellers of their mistakes and we remove the suspicious items from the radar (always!).
Thanks for your help.

neither the dealer nor the listing was
mentioned.
The first port of call WAS the dealer as I offered all the info need to correct the listing.
My comment was just a tounge in cheek view at what we all pride ourselves on, accuracy.
Hell I have too made mistakes and continue to learn.
Maybe my coffee was too strong and my hopes of scoring a ferrari was a bit too ambitious! I will settle for a shelby gt500 cobra instead then.
any willing donors out there with one going for a song??

I am
a bit nonplussed at the reactions to Simon's post. Why is the messenger so often blamed for the message ?
I admit to a lifelong impetus to correct errors, for the admirable purpose (I hope) of eradicating misinformation before it spreads -- and for the lamentable reason that I apparently derive some pleasure in setting the record straight, even if at the expense of the feelings of others. Blame my psyche for that one . . .
I can't see the problem in pointing out an error "in print" -- doing so does not necessarily imply that the printer is at fault !

Perhaps the reaction has...
Perhaps the reaction has more to do with the statement "I have not yet told patrick or Alix but they should know better!"
It could be misconstrued as blame, as a suggestion of ignorance, or even as intentional misrepresentation. Or even as ingratitude for all they get right.
I didn't feel this way, but I could see someone reacting in one of the aforementioned ways. And I can see the point that a private message would be more appreciated by most - so as not to cause public embarrassment or even the bother of having to publicly apologize and/or defend oneself
The very action of publicly pointing out an error can also be seen as being a know-it-all and of using such an opportunity to illustrate that.
It pays to err on the side of careful politeness. But then again, I have been guilty of the same.

Should anyone be faced with...
Should anyone be faced with punishment, could it come in the form of perpetual Aalto stool ID's and distribution/administration of horse tranquillizers?