Originally Posted by
172pilot
This is very true. I have booked multi-leg itineraries through a TA. It is often cheaper to book with two separate tickets but with one PNR. (It's actually multiple PNRs as each carrier will issue their own). It doesn't change ACs responsibility in the case however.
Sounds like it's not really a single PNR. In other words, a single reservation system PNR (Sabre, Amadeus etc.) but really two airline PNRs/tickets.
At the end of the day, just separate tickets.
(This said, cow's link still shows that if a delay is more than two hours AC should accommodate.)