That is interesting.
I was on AI from Bangalore to Delhi, then onward to EWR from there. AI swore to me that, no, they could not register me on that flight and, no, they wouldn't even be able to check my bag to EWR (for customs) because I was on two PNRs, one AI to DEL and another one DEL->EWR (and then to BOS).
AI was part of *A then.
Just ignorance, or the lady was right?