I spent a lot of time in DS's classroom in 1st grade doing those reading speed tests (they were testing for words-per-minute, not comprehension). The rule was that if a kid missed a word, I was supposed to deduct a point (so instead of marking as 90 wpm, it would be 89wpm). I don't recall what I was supposed to do if a word was added, but it never happened while I was testing. I probably would have ignored it, so it wouldn't affect the final score, unless adding extra words slowed the kid down.

I notice myself doing this occasionally when I read out loud. I'll add a word to a sentence in such a way that it doesn't change the meaning, it's just more like the way *I* would have written it. smile DD does it a little bit, too; I don't usually correct her unless it's a major error or change. I should prep her for school, though.