Certainly. The laws don't provide for disallowing it. They do provide for adjusting the score if
a) Unauthorized Information (UI) was conveyed to a player
b) That player chose from amongst logical alternatives one that could have been demonstrably suggested by the UI
c) the opponents were damaged thereby.
The slow tempo of West's pass suggests that he was considering some other action. Given his previous bidding, it seems to me it suggests that he has some support for diamonds, but is concerned about East's holding in that suit. So for East, bidding diamonds seems to me to be "demonstrably suggested", given his good five card diamond suit. Does East have a logical alternative to 3
? Seems to me pass fits that bill. So two of the three criteria are fulfilled. Were N/S damaged by the bid? I dunno. What happened when it was played out? If, as seems likely from the posted hands, E/W made 3
, while N/S can make 2 or 3
, I'd say yes, they were damaged. So I'd adjust the score to 2
making 3, +140 to N/S. Laws 73F1, 16, and 12C2. Also, Law 83 requires the players be notified of their right to appeal.