I think Klink is doing fine. With the hush puppy shoes he was offering alternatives, not asserting anything. There was no proof that JY's feet were in the shoes, and there is no other evidence to indicate that he was at the crime scene.
I think JY also testified that he thought MY donated the shoes to Good Will. I don't think he was certain what happened to them.
I think the better defense strategy would be to say "there is no evidence that JY's Hush Puppies left those prints. We don't even know how many of those shoes HP made with that sole - Mr. Riha couldn't answer that question. But for arguments sake, lets consider if it actually was those Orbitals JY once owned..."