Originally Posted by
SparseFlyer
Everything will be ok. OALs will not add segments on PNRs if it's not their own.
Since it's a UA reservation, as long as the UA reservation shows the entire xorrect itinerary and AC reservation shows at least their own flights correctly, you are ok.
It will be ok at the airport.
This has been discussed before. You will be fine.
If the outbound segment is not in the PNR, it will not load into DCS automatically and thus you will not be able to use OLCI to do all the boarding passes. However, at the airport, they can manually add the flight to ensure first you get your boarding pass but more importantly, get your bags tagged through.