JW testified a lot on the contents of the hard drive as a networking expert and as a security expert. He was only precluded from testifying on forensic contents, like the MFT, on the hard drive.
The system log about a network connection to a router is to rebut the networking expert testimony given by JW. I think it is on point.
He did not testify about the system event logs on the PC. So what testimony would this be rebutting? Did JW say a Cisco router wasn't connected to the laptop or accessed by it? If he did, this would be rebuttal testimony.
Just admit this is new evidence and the prosecution is trying to be sneaky in getting in in. Can you at least admit that? It means nothing...but it is the truth.