Quoting Miss Milk Bags:" I know its so weird!! She is 19inches long! Now they are saying they need to keep the baby an extra week ... [snip!] ... system (god forbid) and they are keeping them there until they figure out what to do!! I just don't know!! It seems so weird!!"
I am sure they would tell her if something was wrong with her baby. At least I would hope. Our NICU forgot to call us when they had to bag (revive) our son late at night after his heart surgery though. I was pissed when I found out the next day. I don't know what I would have done, if I couldn't have been with him in his last moments of life. Luckily everything turned out fine though.
He has to have something going on with him that they wont let him go home though. If nothing is wrong and he is over 5 lbs, he should be able to be released. I know there were a few term babies that were in the NICU with my son that had breathing problems and such, but they usually only stayed a couple days. The hospital never said they had to stay a week as a preemie protocol. As long as the baby can eat, breathe, and well be a newborn baby on it's own without problems, he should be released. Sounds like maybe your friend is leaving something out or something is going on.
I mean, like I mentioned earlier, there are some term babies that go to the NICU because their lungs weren't fully mature or what not, but you said nothing was wrong with him now, so I don't know what it would be.