It's likely that the correct ruling is 'table result stands', but there are a few points of note here:

• Before making a ruling, one needs to determine what E/W's actual methods are; all we know at present is that E/W disagree.
• Despite the given auction not having specified it, 2C and 2D should both be alerted - but neither opponent asked for any explanation of the bids up until after E/W had committed to playing in 2D. As such there isn't any UI affecting their auction and we're purely looking at South's final pass.
• There is only grounds for an adjustment if the non-offending side are materially damaged by the incorrect explanation.
• When N/S state that they feel damaged; then the director should ask South what action they'd take over the 2D bid with the correct explanation and also ask why they didn't take this action with the information given at the table.
• If the director decides that there isn't grounds for an adjustment, then the table result of 2DW making however many should stand.
• If the director decides that there is grounds for an adjustment, then they should figure out what would likely happen at the table and adjust the score to reflect this.
  • This might be something like: 30% of time South would pass 2D for +100 [40 MP], 30% of time South would X 2D for +200 [80 MP], 40% of time South would bid 2D for +140 [65 MP]. As such the table result should be: 30%*40+30%*80+40%*65= 62MP [NB: I made up the results of each contract, and how they'd matchpoint]
• If the TD decides that calculating the likely outcomes would be too hard then they should give an artificial adjusted score of 60/40 (to not damage the non-offending side), NOT 50/50.

The E/W auction would be entirely the same if West had held AKJxx club and Kxx diamond, but 2D would be a terrible spot for them to play the board. The fact that 2D happens to be the E/W par on this board is more 'rub of the green' than anything nefarious.

If West had explained 2C as puppet stayman before East had passed 2D, then there might've been some fun parts to this ruling -- but it should still shake out to East being allowed to pass 2D. If East was 4234 instead of 2434 and their methods meant that 2C was clubs+higher, then 2D would be a pass/correct style bid and it would behoove East to bid 2S as that's their second suit.

thanks brad, a very comprehensive answer and yes, the 2C was alerted, but not the 2D.  East's bid was the correct escape bid after a X, West had forgotten.

Hi Ella

Law75 B1. West should have been called director before making the explanation.  

I believe the result needs to be based on a weighted score rather than an arbitary one. Both are vunerable so part scores and vunerable going light might make this a close call.

Liz