Some time ago I was asked how I would rule in a (historical) case like this. I had a problem with it then and I still do. (I never had any details but have made some up which fit the circumstances described.)
South's double was after an agreed hesitation
5♦ went 1 down; 5♠ would have been 2 down (3 aces and a heart ruff)
North thought he was being ethical by passing when he would normally prefer to bid 5♠ with such a powerful hand but with poor defensive tricks.
East-West accuse South of hesitating deliberately with no bridge reason in order to prevent North bidding on. South said he was honestly considering pass (thinking the best achievable outcome could be defending 5♦ not doubled) or double, but then deciding the pass would probably be interpreted as being forcing.
It does appear East-West were hard done by but what can be done to rectify that?
Where is the infraction?
Looking at Law 73:
D1 says to vary the tempo ... in which a call or play is made is not in itself an infraction
D2 says it is wrong to deliberately mislead an opponent through hesitancy but the opponents have not been misled here.
Law 16B says the score can be adjusted if a player chose from logical alternatives one that could demonstrably have been suggested by partners tempo. But how can Norths hesitation DEMONSTRABLY suggest South should pass? (A slow double indicates that player was considering something else which would invariably favour taking the double out with a marginal hand).
Nor can I see Law 23 applying an offender could have been aware at the time of his irregularity that this could well damage the non-offending side. There is no offender here because as we have just noted (quote from Law 73D1 above) a hesitation is NOT an irregularity.
So what can the director do?
Just tell East-West they were unlucky? Or is there an explicit law North or South can be deemed to have broken?
Or should he tell North his explanation for the hesitation is unacceptable (although in my view it seems plausible)?
I have my own view which I have posted in that forum. But I would be interested to see views here.