The following is from Bibliotheca Sacra, Volume 35 (1878) pg. 785-786: A few arguments against verbal or dictational inspiration can be gleaned from the described attempt to defend it.

Dr. Cunningham is valiant in answering various objections against his theory [i.e. “complete and plenary verbal inspiration”]. Thus “Paul sometimes discovers a doubt and a change of purpose as to the time of his journeyings,” etc. (Dr. Hill); but Paul was verbally inspired to express his doubt and change of purpose (pp. 3380, 381). He spake as a fool when he boasted; but he was verbally inspired to state that he thus spake (pp. 382, 383). The evangelists differ from each other in repeating the same discourse or sentence of our Lord; but the Spirit accommodated himself to the faculties of the inspired men, and in this accommodation “left room for whatever diversity in their narratives was consistent with their veracity and accuracy” (p. 383). The verbal differences found in uninspired witnesses are deemed a sign of their truthfulness. Is it quite certain that such verbal differences “could not have been produced by the Holy Spirit, who had resolved to use the instrumentality of men’s faculties in this matter, and to use them in such a way as to make the works produced contain plain internal evidences of their integrity and veracity as men?” (p. 387). The author of one Gospel may have quoted from a previously written document; in directing him to quote from it the Holy Spirit directed him to use the words of it. In 1 Cor. vii. 12, the words “I speak, not the Lord,” were suggested or dictated by the Holy Spirit. It is commonly objected to the doctrine of verbal inspiration that the writers of the New Testament do not cite the Old Testament in its exact translation, but cite it in the translation of the Seventy, even when this translation is inaccurate. Dr. Cunningham, however, founds an argument for verbal inspiration on the manner in which the New Testament quotes from the Old. He refers to those passages “in which Christ and his apostles manifestly base an argument upon the precise words employed in the quotations they adduced from the Old Testament. This we find they did in many cases, and this affords a proof that they reckoned the Old Testament verbally inspired” (p. 369)
There are some objections against his theory which Dr. Cunningham does not answer in a very positive way. He admits that “Christ unquestionably promised his apostles verbal inspiration when they should be brought before kings and rulers” (p. 365). He would of course admit that the promise made to the original disciples extended to the apostle Paul. Paul, then, had the promise of verbal inspiration when he was brought before the Jewish Sanhedrim [sic]. But Dr. Cunningham says: “There has been a difference of opinion among commentators as to the warrantableness and the innocency of Paul’s conduct recorded in Acts xxiii. 6,7; some holding that it lay within the limits of legitimate prudence and dexterity, and others that it did not, but partook somewhat of the character of an equivocal artifice. The inspiration of the Scriptures is not affected by these doubts or difficulties about some of the actions of good men recorded there, and neither is it affected by similar doubts or difficulties in regard to some of their sayings or speeches, which are also recorded without any very certain intimation being in all cases given to us as to whether the sayings and speeches were themselves suggested by the Holy Spirit, and in all respect accordant with God’s will” (p. 351). See also the remarks on the speech of Stephen (pp. 351, 353)

I’d like to find the works of the Dr. Hill referenced above, but annoyingly in these old books they insist on calling writer’s Dr. So-and-so without ever giving their first names!  Even so, I found the following reference in another book (Inspiration: The Infallible Truth and Divine Authority of the Holy Scriptures (1865), pages 249-250) which makes further reference to Dr. Hill’s theory of inspiration:

With many divines, such as Dr Hill, three different degrees of inspiration were believed to be sufficient to accounts for the facts of Scripture, and were found in its pages,–the inspiration of superintendence, of elevation, and of suggestion. An investigation of the phenomena of Scripture induced others, such as Dr Henderson, to multiply the number of varieties to five,–the inspiration of excitement, of invigoration, of superintendence, of guidance, and of direct revelation. But whatever the forms under which it is held, or the number and variety of classifications of the divine element believed to be exemplified in the Scripture text, the fundamental principle is the same. Where nature ended, there inspiration began. When the unaided powers of the penmen were insufficient, a measure of divine help in the exact ratio of the insufficiency was furnished. In proportion as the human element was present and active, there the divine element was absent or passive. Inspiration was meted out in the degree in which memory, or judgement, or expression of the part of the writer failed. The Spirit of God waited on the weakness of man, as the graduated supplement to it.
The origin and occasion for this theory cast no small measure of light upon the character of it. It was introduced avowedly for the purpose of meeting the allegations of error and imperfection in Scripture, and in order to reconcile the existence of real defects with the belief of a divine agency employed in the composition of it. And had there been any foundation of truth in the theory itself, it would have answered the purpose for which it was used. Wherever imperfection existed in Scripture, it was sufficient for the advocates of such a scheme to say that there the human element was present to the exclusion of the divine, and that the error was due to the former in the absence of the latter. The theory was undoubtedly based upon a compromise between the friends and the enemies of inspiration, in which the enemies were allowed to retain the error which they alleged in the sacred volume, and the friends were enabled to account for them, while yet retaining the general doctrine of an inspiration, at least in name.
But the compromise was one fatal to the character of the theory itself. It allowed of the introduction or error into the infallible text, to an indefinite and unknown extent….

The extent is fairly well known, actually: anything that Paul wrote is in error, unless he is merely telling us how the real apostles practiced things.  Where he disagrees with them and seeks to supplant their practice or beliefs with his own, there is putrid error.

Woohoo, I’ve found Dr Hill’s work. Lectures in Divinity – Volume 1 (1833) by George Hill, page 246:

Paul sometimes discovers a doubt, and a change of purpose as to the time of his journeyings, and other little incidents, which the highest degree of inspiration would have prevented. It is allowed that there is a degree of imperfection and obscurity, which, in some instances, remains on the style of the sacred writers, and particularly of Paul, which cannot easily reconcile with the highest degree of inspiration. Once more, there are peculiarities of expression, and a marked manner, by which a person of taste and discernment may clearly distinguish the writings of every one, from those of every other. But had all written uniformly under the same inspiration of suggestion, there could not have been a difference of manner corresponding to the difference of character; and the expression used by all might have been expected to be the best possible.

Certainly the least offensive thing that can be said about Paul is that he’s a crappy writer who just can’t figure out how to get his point across, and as a result, for 1700s years or more (depending on when the person going by the name “Paul” wrote) the majority of his (or her, or their) readers (depending on who really wrote the epistles) have not understood the actual point the author was trying to make, nor did they ever have a chance since the writing was so crappy from the get-go that nobody could possibly understand it.