Earlier quoted context omitted.
I think the person you replied to was objecting to the fact that the wording makes it sound like we're using humans as vessels for extending the life of pig organs outside of pigs. Not necessarily that 6 months is a short period of time.
That's an interesting way to interpret it! I see what you mean, but I still can't see myself interpreting that headline in that way. Does it really give that vibe?
"This is the longest a pig organ has survived in a living person"
The pig organ is the first thing mentioned, with the living person last.
Whereas:
"This is the longest time a patient has survived after a pig organ transplant."
This puts the patient first, and doesn't give as much of that kind of vibe.
Edit: Actually, that updated sentence may need some adjustment. I assume when organ transplants fail we don't just let people die with them. So maybe that's why the original sentence had such emphasis on the survival of the pig organ...