How do you know the bombs didn't hit?
Also bombs do a certain amount of "splash" damage from what I've seen. It may not have hit directly, but may have been just close enough to finish off the CV (if it had already been severely damaged beforehand)
As far as landing your plane severely damaged.. well congratulations! Yes it is sometimes possible to fly and even land a severely damaged airplane (ever seen footage of the commercial jet landing with most of it's skin missing?) as long as its "critical" components are still somewhat intact.
