One-stop direct flights always show as two separate lines on aa.com, but that's just the way they format the information. In this case AA1830 does exist and can be taken as one OWE segment. Good catch, by the way, I didn't know about that one. Thanks!

Edited to add: (a) this is one flight I would most definitely protect with a dated coupon. (b) the options available for a non-transcon Central America/Caribbean JFK-XXX-LAX triangle are so few that this flight is a great find.