What’s happening is that you can tell the camrera to output 1080i out of the anolog component outputs, handy in some applications like when shooting live to match other cameras. Even so, it will still record to tape as 720p.
Hope this clears up the confusion.
BTW- don’t think that 1080i is better than 720p (Europe chose 720p as their HD broadcast standard over 1080i). Read up a bit if your confused. Just google 720p vs 1080i.