There was lots of field protection on this, because apparently none of us previewed GIB's understanding of 4♥ before making the bid. Unfortunately, I can't say what 3♥ would have meant instead of 4♥, because none of the 8 Souths who bid 2♦ followed it with 3♥.
4♥ is described as 6+H; 5+S; 25+ total points. I realize that, theoretically, North could have a yarborough with 2 hearts, but isn't this a little extreme?
One player (maybe realizing he didn't have 25+ points) chose to bid 3♦ over 2♥. GIB understands this bid as 4+D; 5+H; 5+S; 18+ total points. It gets the strength right, but I think GIB should reconsider the distribution.

Help

(1♦)-2♦-(p)-2♥
(p )-4♥-(p)-4NT
(p )-5♦-(p)-6♥