OK, that might make sense.
But in this case my score was 380, with 0 kills and 14 deaths. I was in the GDI base once for about 5 seconds on the initial rush and then killed. I spent the rest of the game in the Nod base as infantry defending Nod Harv from Meds, MRLS, and APC . I had no offense score as far as I can tell.
That's why I think maybe the Offense and Defense MVP names are switched.