While I agree that it isn't right, it is the way of both parties, and both have done it in the past.
I don't recall now, but think it was during Bob Dole's nomination convention they did the same, but with more finesse. In stead of the nervous bungling the chair said: "In the opinion of the chair the yeas have it," and moved on.
It isn't right, but neither party will let the delegates change something that they don't want changed. It is the way of things.