...Do you think it's possible you were hit with something other than the rock first?

Like... just to try to explain that, if someone were to hit you with a blunt object but not break the skin, you could still be unconscious and injured when Urashima and Inaba found you. If they hit you later with the rock, after killing Urashima, they were maybe trying to... hide what you were actually hit with?

[...???? Maybe??]