UK, Imp Teams of 4 KO match, Love All, Dlr W.
1N(15-17) 2C checkback
5C 5D after 5 min think
NS reserve their rights. While thinking about his lead, North asks about the bidding and the following discrepancy comes to light.
According to West, 4NT was RKCB, 5C was 0/3.
According to East, 4NT showed a bad hand for the bidding so far, and 5C was a further slam try with CK.
North leads HQ
6D makes when North fails to split from SQJx at trick 2 and trumps split 3-2.
Please explain what should the ruling be?