A counterclaim is an argument that goes against the one previously presented. In this case, the claim is that Chelsea got wet because she was walking outside while it was raining. A counterclaim would be an argument that did not defend this. An example of a counterclaim would be that Chelsea got wet from the water that was inside her bucket.
The evidence that would be necessary to support this counterclaim would be that the bucket is wet on the inside, proving it previously had some water.
