Those stories are very interesting ones and are nice illustrative examples of the limitation of the DNA recognition process. The most surprising (funny?) one is that of the baby who ate their twin brother. I didn't know this was even possible!
However, I can easily assume that those stories are exceptions among many generalities where nothing weird happens. What do you think?
Yes, you are right! Every technology has its limitation, as such there should be a room for further investigation after DNA results in order to cater for those exception.