I think Prof Ehrman has said that Matthew is not believed to have known of Paul’s writings, or at the very least not believed to be influenced by Paul to any noticeable degree.  I’ve asked him before if he thinks that Paul influenced ANY of the gospels and I infer from his vague response that the answer, at least for him, is “no”.  This topic is of interest to me because I think that the “good works” preaching from James’ epistle (I assume that’s what you mean when you mentioned James) is closer to what Jesus taught.  So, how did the earliest Christian communities and the ones slightly later (from the time of the writing of Matthew, Luke and John) view Paul’s view of “faith alone”?  The answer, that I’ve read at least, is that the gospels, Mark and Matthew, at least I think, are not influenced by him.  There are others on here who will probably have a more concise and direct answer, but that’s my input.

Good question, though….. 

Matthew 25 is basically just three pericopes: two parables and the “message to the nations”.  I’m no expert, but it seems like if there was interpolation in any of those Prof Ehrman would have mentioned it either on the blog or in one of his books.  Of all the interpolations he’s mentioned by and large they are small changes that make a big difference (with the only exception I can think of being the woman in adultery in John).  

The only other point I can make is that Matthew’s gospel stands in strong support of Mosaic Law and that would be in opposition to what Paul preached.  It doesn’t seem likely (to me at least) that Matthew would cherry pick something of Pauline influence for a small part of his book.  We’ve seen what communities do who disagreed with Paul’s message like Rome which virtually ignored him him for a couple of centuries.  I think in the very early church supporting Paul’s message was an all or nothing thing.  You were either all in with what he preached or you were in opposition to him.  You either supported the Law or you thought Jesus fulfilled the Law and strictly following it was no longer necessary.

I was looking for something else on the site just now and I came across this blog post that Prof Ehrman made just a few months ago on this very topic of Matthew compared to Paul.  Here is a link to the first of (I think) two posts on Matthew, Paul and Mosaic Law.  These two were part of a longer sequence of blog posts though on the topic of Paul and some of his enemies.  ** you do not have permission to see this link **