South opened a 5-4 and apparently wasn't 'used' to it. He didn't want to let them play if he couldn't show his two suits. Why would North use Stayman without a Major? And since North didn't support hearts s/he should have spades... So maybe South should double 2♠ as his hand looks like it will fare well against 2♠ defensively when partner holds 4 spades. But why did North use Stayman? With such a weak hand (not even good enough for an invitation) North should have waited to enter the bidding. And why didn't North double 2♠ when s/he knows there's no fit in that suit for the opponents. So I blame both players and probably it's 60-40 or 70-30 but to know exactly the methods should be explained, what would further doubles mean, etc