This isn't entirely analogous, but maybe it can be a helpful reference.
Last year, I flew HND-ICN-DXB-JED on a KE-ticketed itinerary, with the final leg flown by SV with a KE flight number. Therefore, KE's earning rules apply. However, on the return flight, my JED-DXB was canceled and we were placed into an earlier flight, also by SV, but when the mileage came due, I earned the first segment under SV rules instead of KE's as that's how the new flight was marketed.
One email to DL and the issue was resolved instantly. Even though this was ST, I can't imagine DL's actively trying to get out of giving mileage credit to people if the request is reasonable enough.
I would call AM and see if it's possible for them to route you on KE/DL (via LAX or SEA)...