This hand is very interesting,the most strange things are bidding style with two Gib's explanations which I can't understand.
1- A pity we lost grand slam:
If Gib N can cuebid 4♦ followed by 4♣,I must rebid 4nt,such I am very very easy to bid up to 7♠.
2- After 4♣,Gib N cuebid 5♣ strangely instead of cheapest 4♦ ,and Gib denied ♦A twice on the both of 5♣ and 5♠ explanations .