I don't think it is necessary. Unless you can defeat the defender you should not get their resources.

When a thief tries to steal your wallet on the street and you engage in a battle and knock each other both out, the wallet still remains in the pocket of the victim.
That should also be in a raid, the resources still stays with the defending player in a tie.

I'll go ahead and put my vote as a no on this one. See: Kick's statement.

I say no

Merging topics.