At neither table was 3♠ alerted. Both NS pairs play basic cue-bidding in which first-round controls are shown before second-round (with some exceptions).
The North player at the other table jumped straight to 6♥ over 4♠. This North would probably have done the same had 3♠ been alerted, but thought that this would discourage South from correcting the trump suit to spades, so considered it a breach of law 73C and embarked on a round of cue-bidding. I rather suspect they should have continued with 6♦ over 5♥, but having made a token effort, they just bid the contract they wanted to be in all along.
At the other table justice was served when South corrected to 6♠, and 7♥ went one off.
What do you think North's logical alternatives are over 4♠ and 5♥?