So either the new rule needs to be changed to read "most scoring plays will be reviewed, when the refs feel like it" or they need to review field goals.
The technology exists to check. If the NFL is too poor to buy it maybe they should cut back on some of the multi million dollar contracts so they can afford it.
The other guy who said something about positioning an object in 3D space requires multiple angles... you are correct, but 3D space is not the issue here, 2D space is. All they needed to know is if the ball crossed the line created by the edge of the upright or not.
Say what you will about the NHL being locked out and whatnot, but they are WAY ahead of football when it comes to using camera technology to improve the game.