I can kind of excuse that on the basis that they obviously only have a few preset phrases that they can string together for the live text commentary by clicking a few buttons, and "scores direct from a corner" presumably so rarely happens that it just isn't on the list, so "just outside the box" is as accurate as they could manage. It's a poor system that can't be over-ridden for the occasional edge case, but such is life.
I'd agree that Sportscene really isn't worth watching any more though... apart from being able to watch the goals on MFC TV before the BBC show them, the online BBC highlights are usually longer and better than Sportscene's anyway, and without the mediocre discussion afterwards.