One South overcalled 1N, showing 15-18, and was passed out there. Here, Isabelle shows 19-21. North shows his two suits.
Jim chooses the presumably correct sequence, showing 22-25. Why does GIB rebid diamonds, instead of giving South the choice of minor, if he's not going to leave in 3N? Some of us bid 3N directly over 1♥, which showed 25-30, and North passed.