(BUG?) (ionItemReorder) returns wrong indexes when dropping item back in it's original place

the $event object returns the wrong .to index when dragging an item up or down, then while still dragging it, dropping it back to it’s original place.
you would expect the .from and .to index to be the same value in this case, but instead it returns the .from index +1 or - 1 depending on the last direction.

eg. dragging index 1 to index 3 then back up to index 1 and dropping it. will return, Object {from: 1, to: 2}
dragging index 3 to index 0 then back up to index 3 and dropping it. will return, Object {from: 3, to: 2}

is this a bug, or am i forgetting something? I’m using ionic2 rc0

thanks.