This is a good illustration of a situation which frustrates anyone who analyses the hands and the results. On this board slams can be made by N/S in any of Clubs, Hearts or No Trumps. Nobody bid a slam and nearly everybody made 12 tricks in something! An unusual feature of this hand is that there are 12 tricks off the top with the only luck being a 3:3 break in hearts. Are we all making bidding errors?
Take a few minutes to have a look. Assuming a weak no trump is being played, the opening bid is likely to be 1C from S. N has 9 HCPs and 6 card support. He has 7 losers with a singleton diamond. Of his 7 losers 3 are in the likely trump suit. In normal circumstances this suggests a bid at the 4 level on the Losing Trick Count but there is and should be a reluctance in the minors to go beyond 3NT on the first round. Some will play conventions which may help (Inverted minors and/or splinters, the latter being unusual after a minor is bid) but for an average club player one would expect to bid 3 clubs remembering that this undervalues our hand.
With 5 losers against an assumed 8 and a singleton diamond ace South is likely to stick with Clubs. A bid of 5 clubs will almost certainly close the auction whereas a bid of 4 clubs looks better in practice but is unattractive. Bidding hearts is poor as the raise by N denies a 4 card major. How about 4 diamonds showing Ace or void in the suit and still leaving 5Cs as fall back? I quite like this bid as it is constructive. Now 4S from N will show AS and S could now bid 6C in the knowledge that all 4 aces are held. Chancy perhaps but reasonable.
The more observant will be wondering what the opponents were doing! With 11 diamonds between them interference is quite possible. When opponents do get involved you should think positively as they give you another suit to bid with no risk of your partner thinking you actually have the suit! Think how good it is safely to splinter or cue bid on this hand and you also do not have to worry about a pass from partner. In addition, interference to a high level (5Ds, say) may well push you into the makeable slam!
To illustrate what might happen after interference, the auction might progress: Pass, 1C,1D, 3D (splinter showing a singleton or void), 5D, x, Pass, 6C....job done!
The lesson here is to give full value to the N hand. Only 9 HCPs but strong playing values. Once S goes on after 3Cs, N should start to think that a slam is possible. You may not reach it but the art of slam bidding is to recognise when a slam is possible and then to exercise some ingenuity to keep the bidding going as long as you are able to stop in game if you get "wrong" answers.
All of this begs a question - " Should I be playing in a slam depending on a 3:3 break?". In life as in bridge the correctness of the decision depends on the outcome!