Well seeing as the Bible is a collection of different books written by multitudes of writers over a span of several hundred to thousand years, re-translated multiple times and gathered together by churches usually at their own discretion, of course there's going to be contradictions.
Heh, I might actually be work with Prof. Ehrman if I get accepted to UNC Chapel Hill's program this fall.
While I haven't read his books, there is a historical truth to what he is generally saying. St. Jerome first translated the Bible into Latin (the common language at the time) using as original of texts as he could obtain. However, since then, the majority of other translations and retranslations have been based on Jerome's translation, the septuagint (aka, Greek translations of old testament), etc. It wasn't until Martin Luther that there was a serious return to original sources (and one might note, Luther was not a fan of the book of James). Even then, the practice of retranslation original texts has not been strictly followed since. However, I would have to depart from Ehrman there; the texts are fairly stable and show little to no signs of intentional modification.
Certainly, large sections of the gospels have been misquoted (I am assuming he limited himself to the Gospels, since the other books of the New Testament do not include direct many statements by Jesus, unless one counts the vision of Saul and the book of Revelations). However, by in large, the New Testament and the Old Testament are the two most "accurate" historical records in existence. I say "accurate" only in the preservation of original form; accurate in terms of spiritual or historical truths is something I am not here commenting on.
For one, the modern and commonly accepted books of the bible we cited as being divinely inspired and referenced by early Church fathers. If I am recalling correctly, the books commonly held to be canon were established as early as the second century. Additionally, even if a single original text did not survive, the entire new testament could be reconstructed based on the quotations provided by Church fathers. However, that is not the case; the earliest texts date from the first and second centuries (though to be fair, there is debate in historical circles regarding this; some place the earliest texts at the 4th century or later). Additionally, there are quite literally hundreds of copies of the texts (many complete, some not) dating from early periods as well.
To put this into perspective, most historical records from this time period exist in small numbers (10~30 copies, if we are lucky, usually less) and those records are of late origin (usually the earliest copies date to around 300+ years after the events, but 1000+ years is hardly uncommon).
Then of course there are the extra-canonical texts (Apocrypha, etc). Jerome excluded books that were not written in the original language (such as Greek books of the old testament) and those that were of limited acceptance. These books of the bible were not said to have been irreligious, rather they did not hold the same authority as more reliable works. They were said to still potentially be valuable resources. However, as time went on, these books were included less and less, until we get to the modern era in which most Christians are unaware of them and disregard them when they are so aware.
There is another consideration that is important to this matter; that of linguistics. It is incredibly difficult for a later writer to mimic earlier writing styles. The bible shows few to no such traces (I only qualify the statement because I am far from an expert in the field). To offer an example; words change meanings fairly often; it is a common mistake of manufactured and altered works that words are used to mean something that, at the intended time period, would not have meant that. Static as we use it today means without change. The original Greek word from which we get Static means something closer to "unceasing chaos and revolution." And of course, revolution as something that means change is a fairly modern definition as well. Other markers of tampering are in lettering, spelling, grammar, etc.
Something to note, is that Ehrman is approaching a historical issue from a non-historical background (he is a Religious Studies professor, as opposed to History professor). While this should not look ill-favorably on his work, it should raise the expectation in the reader to find collaborations with historians, citations of academic historical works, etc. A different perspective is often invaluable in academic study, but one has to be extra careful in working significantly outside one’s field of expertise (and in turn reading works by individuals outside their field of expertise).
One thing I find interesting is the attitude of Lutherans compared to other protestant denominations and Catholicism towards other walks of life. Baptists and many other protestants seem to be the most vehement in regards to going on the warpath over issues such as homosexuality and abortion, and Catholics seem to concentrate on defining right and wrong in what seems to be PSAs from the Vatican. Lutherans on the other hand, don't seem to be up in arms over anything in modern society, or if they are it's not as well documented.
Heh, studying the various Christian sects and how they split off, merged, and changed over the years is incredibly fascinating. Lutherans were the first wave of reform from the old Catholic church and though quite different at the time, compared to later revolutions they are still fairly similar. The anabaptists were after that and tended to break with traditional whole hog (said by someone who grew up in a Baptists church). Luther had a respect for tradition and seemed to generally want tradition to conform to scripture, but anabaptists saw tradition as inherently flawed.
Then there are those of the evangelical movement. You can generally tell how radical a church is by what they define spiritual gifts as. These groups include Vineyard churches and others that are generally seen a "ultra conservative" and "anti-this or that." I actually find it hilarious that the most radical Christian sects are seen as the most "conservative."
Anywho, Methodists (of which, as of yesterday, I am now counted among) are also a fairly peaceable bunch. Started by John Wesley, the sect generally says that changes should be made only after due consideration (so don't throw out tradition hastily, but don't cling onto tradition either). They also generally have the approach of: "In essentials unity, in nonessentials liberty, and in all things charity."