well, to be honest, this is pretty risky. you could have reported the actual transcript and explained that these courses lowered your overall GPA in your additional essay. This would be perfectly acceptable. but now, i don't know...
I wouldn't worry too much. The school has spent time and manpower reviewing your app and interviewing you. So as long as they don't find major issues such as forged transcripts or fake recommendations, you should be fine. My suggestion is, don't get paranoid, but be prepared to answer inquiry from the school.
Not sure what will happen if they can not verify your transcripts, though. But the "presumed innocence" should always stand, I believe.