2♣X went 2 off. East informed opponents at the end of the hand that partner had failed to alert his X as a support double. EW have support doubles marked on their convention card. NS called the director and claimed damage - South claimed he would have bid 2S had he known it was a support double.
Director was called and she ruled that the table result stands.
NS appealed. The appeals committee was told by EW at the appeal that West had simply failed to alert. EW are not a regular partnership but they had a board earlier in the session where support doubles came up (against a different pair of opponents). East also argued that South could have protected himself by enquiring about the double. NS claimed that the double was not alerted hence the assumption that it was for takeout. S claimed that it would be difficult for him to pull to 2♠ without the alert and he would have done so if it had been alerted and explained as being a support double.
How would you rule if you were on the AC?