Sounds unpleasant and glad you made it okay. The Taipei Hyatt is not a bad place to be stranded for an extra night though. IRROPS going badly at some outstation is always my fear on complex award tickets.

Did you give them the CA PNR or the US PNR?

I always make sure to have all of PNRs for various carriers printed out and onhand as this usually helps the agent understand and see the full routing etc.

Also sometimes better in these cases to just present yourself at the airport, where it is much harder to get rid of you than on the phone!