Under the statement, inerrancy applies only to the original manuscripts (which no longer exist, but which can be inferred on the basis of extant copies), not to the copies or translations themselves. Most of all it does not refer to a blind literal interpretation.
However, in determining what the God-taught writer is asserting in each passage, we must pay the most careful attention to its claims and character as a human production. In inspiration, God utilized the culture and conventions of His penman's milieu, a milieu that God controls in His sovereign providence; it is misinterpretation to imagine otherwise.
So history must be treated as history, poetry as poetry, hyperbole and metaphor as hyperbole and metaphor, generalization and approximation as what they are, and so forth. Differences between literary conventions in Bible times and in ours must also be observed: since, for instance, non-chronological narration and imprecise citation were conventional and acceptable and violated no expectations in those days, we must not regard these things as faults when we find them in Bible writers. When total precision of a particular kind was not expected nor aimed at, it is no error not to have achieved it. Scripture is inerrant, not in the sense of being absolutely precise by modern standards, but in the sense of making good its claims and achieving that measure of focused truth at which its authors aimed.
Besides, some of the pastors who signed it promoted theistic evolution instead of intelligent design.