Yes I agree it's desperate way of fight.
But why a warship is not allowed to be fully repaired in neutral harbour if it even can't normaly sail ? Damn Hague convention is ****!
To loose such a ship in such way ? Common! there had to be a way out without loosing it ?!
On my opinion it could of been enough to repair engines, this was a fast ship and it had big chances breaking away from a pursuing cruisers.
After that a local intel could be done by temporarily recruiting let say a local fisherman with his boat and a german sailor to gather info about how many warships are waiting outside the harbour and which path to choose for escape at night.
I don't believe it was no choise but to scuttle the ship. There was at least a few.