Yeah, I agree with your husband that they were flashbacks for Jin, but forwards for Sun.
I really liked this episode, even though I was sad to see Jin die. One thing that really confused me though was the dates on the tombstone. There were 3, which kinda threw me to begin with, but I figured maybe it was a double plot for him and Sun when her time comes. But the dates, as I remember anyway, were 3/20/80, 11/27/74, and 9/22/2004. I took that to mean that Sun's birthday was the '80 since it had no other date near it. Then Jin's birthday was the '74 and his death date was 9/22/04? Isn't that when the plane crashed? Or around that time, anyway? I know Lost time now, or last week, was Christmas Eve 2004, so are they saying he was dead all of that time? How do they explain the baby then?