Running away is the best option. No shame in living another day.
However, knowing ideal situations dont happen that often, I think that I might injure an attacker, even if I dont want to. Whatever happens, happens!
The nicest and softest techniques in aikido are only as nice and as soft as the falling skills of the attacker, so he probably smash his head to the ground, which would definitly be a good way to get seriously injured.