Spoonerism for words?
You seem to be angling at the idea that this transposition is accidental, not intentional. In that case, you might take a look at synchysis, which is an inversion of word order not being done for emphasis.
A generic term for using words out of normal order is hyperbaton, but that includes all sorts of softer transpositions like "life aquatic" and Yoda-speak like "Gone to the dark side, he has."