I remember back in 1996 when almost every pollster was predicting that Clinton would win by 20+ percentage points. I think one had Clinton up by 25 points over Dole!
Only one lone pollster hit it on the money and showed Dole losing by 8% That was Zogby. Of course, he has managed to live down his reputation ever since.
So yes, one lone pollster all out on its own can be and in times past has been right, and the rest of the herd wrong.
That said, Gallup (like Pew) has a past history of wild swings in its numbers.
I remember that well. Few places reported Zogby because his polling did not conform to the image the media wanted to create. Rush Limbaugh was one of the few who ever mentioned Zogby.