For what it's worth, I've never heard of this. I have to admit I find it pretty unlikely. Even in pre-planned MD/PhD program, I think the majority of the time is spent on the MD, i.e. my understanding is the first two years are spent on med school classes, plus extra classes for your PhD topic. Years 3 and 4 are then spent finishing your dissertation, defending, etc. Then, years 5 & 6 are normal, clinical years for med school. An actual MD/PhD can feel free to correct me here...
If you're very interested in practicing medicine, maybe research becoming a Physician Assistant. They spend their days much like a physician, and you only have 2 years of training and no residency. Or go for broke and get the MD. Whatever makes you happy.