Can't be toast IF there was some oil in it, it seized quickly, but still moved "some". Probably locked up temporarily due to overheating and friction. Pamper it, whisper to it, use lots of oil, and see if it will come back.
Go easy on it too if starts. It's going to smoke, don't panic. It might clear up after a few minutes. But if it's REALLY clacking, shut it down quickly! Probably have damaged rod bearings or piston bearings. Save further damage and commence tear down. :-(