At the table, N put out a STOP card prior to anyone bidding. Before she was able to complete her skip bid, she was told that she was attempting to bid out of turn and I was called. Since her skip bid could have been anything (2C as well as any weak preemptive bid), I allowed her partner (dealer) to call but ignore extraneous information from partner (16B1(a)). S passed and W opened 1C. I instructed N to repeat the call she intended when she originally placed the stop card on the table, and she bid 2H. I allowed the auction to continue as diagrammed. They were off 4 for a bottom. All other tables in the section had NS in 4S making 7.
On reflection, I think when I instructed N to repeat the bid she intended, I should have made her partner pass at his next turn - using 31 A2(a) as guidance. If she had elected to make any other call, I could have barred her partner from the auction. While others I have consulted have suggested that N placing the stop card on the table is tantamount to bidding and I should have barred her partner from the outset, I continue to believe that no one knew what she was about to pull out of her hat and her partner should have at least had a chance to have his voice heard.
Thoughts?