Bummer for sure. In January 2011, weather was a CF in DFW, so AA rebooked me SMF-DFW-DCA to DL SMF-MSP-DCA. Incidentally, SMF-MSP was delayed (mechanical), so once arriving to MSP, I got a hotel, meal vouchers, and a transportation voucher at DCA.
Definitely a memorable trip; was in no hurry to get back to DC, so didn't mind the delays. If there were no interline agreements back then, I'd be stuck with AA in DFW without a comped hotel, or end up having to schlep through LAX as the only other connection point from SMF at that time on AA.