Anyone had experience standing by for a flight from a different airport (and not co-terminal) to the one listed on the ticket.

A friend is scheduled to fly from SJC-STL later this week on TW, but is down in LA now, so they have to catch a LAX-SJC flight on AA. There happens to be a TW flight departing LAX for STL nonstop at about the same time as their LAX-SJC segment- any chance that TW would let them go standby on the LAX-STL flight? I know that you can standby for earlier flights from the same airport, but this is a little different situation. Also, who would you check w/ in this case first- AA or TW?

It helps that AA/TW share a terminal at LAX for these particular flights, but they're not officially integrated yet...

Any suggestions would be greatly appreciated.