I would have a hard time taking this info seriously, mainly because it happened so long ago. Even assuming that she remembers everything perfectly clearly--and chances are she does not--well, so many things have changed since then in terms of our knowledge of pregnancy, labor/birth and neonates, our abilities to monitor and help moms and babies both.
Yet I also have to question the 'low apgars that seem to have been *caused* by a collapsed lung'. Babies are born with their lungs un-inflated, and have to inflate them properly through beginning to breather! As others have indicated, *maybe* that baby was just taking some seconds longer to initiate breathing than med staff were comfortable with, and they overreacted even though he was basically ok to begin with....maybe cord was cut too soon and baby did not have the option of a slow-ish, gentle transition from cord-flow oxygenation to breathing....and then, maybe NICU staff themselves caused the collapsed lung after they took him away from her. And maybe NICU staff did, or maybe they didn't, know that they caused it--in any event, they probably said it because that is what they wanted to believe whether or not they had any idea what caused the problem. I find that med ppl (and other health providers as well, to be fair) are quite often very hard pressed to ever admit that the care they administered was--or could well have been--the cause of harm or any bad condition people might experience. But there is plenty of evidence that med procedures and medications DO have potentially serious and even lethal side effects/consequences for all people-- particularly true for neonates, who are so vulnerable in various ways.
Maybe this had nothing to do with overreactive or otherwise improper med care, also to be fair--but I do have to question how a baby gets born with a collapsed lung. And I do have to question the accuracy of this well-meaning friend's memory. The way memory actually works ordinarily, and with 'peak experiences' and 'traumatic events' especially, our memory-formation is fundamentally impacted by our emotions at the time. She may feel she has perfect recall but doesn't even realized certain facts she missed/distorted. It is also true that in making their report to her about the problem, med staff may have stated it all in 'simple laymen's terms', a shorthand they believed she would best be able to understand at the time. I don't offer this as a criticism at all--many people would have a hard time understanding medical knowledge and terms, and many would *want* no more than such a simplified explanation....they trust the docs, and don't feel much need to know in detail. Just saying that what she was told may have been so simplified as to not be entirely accurate.
Anyway....you can sure appreciate her concern that prompted her telling you this tale, but I hope you will take her story with large grains of salt. I do not claim that bad things--highly unexpected bad things--never happen at homebirth; we have to plan for the best and be prepared for the worst in any event. Just saying that you really can't take her story at face value for all the reasons above.