It was mechanics. Of course it was. They went wide. He didn't hit it where it should go. Your answer didn't address any of the reasoning, just pointed out obvious results.
Compare it to golf if you'd like, but remember, in golf, it's all on the guy swinging the club. Even then, a noise alone can be enough of a distraction to throw the golfer off, and create a bad shot. So, amplify this to a kicker, where others are part of the equation, and you might find that it amounts to more than his mechanics were off. Even a ball placed 1" off center where it should be placed can create a lot of movement left or right because the kicker has already started his motion and picked the spot where he will make impact on the ball. He doesn't decide that as he plants his foot and starts his leg swing. By then, he has very little options. Even a tilt, or a little too much pressure on the ball by the holder can cause a kick to go low, and be blocked. Lots of variables. Not all mechanics by the kicker.