Very sorry to have annoyed you by not having an acceptable title.

Obviously I did not want Southwest credit as I said in my original message "I have never given Hilton my WN# ...." To be painstakingly clear about things: my Amtrak# was linked to the original reservation, I never changed that in any way before arriving at the hotel (nor since), and Amtrak showed as my preferred double dip (with the green check mark) along with the mysterious WN# in my double dip partner options list after the stay posted. I feel my reference to "send the 500 points to AMTRAK" was a fairly clear implication that was what I'd wanted, but I suppose I could've added "as per my reservation" to underscore that it wasn't a matter of my having "changed my mind" later.