I went to error-ref.com to search for pre strike lamination errors images but none were available. But, it doesn't look like any of the post strike images.
The problem is that you could have 1,000,000 lamination errors and none of them could look the same. Chris
Might be a strikethrough of a piece of clumped lint. Belly button lint. Tiny piece of paper. Whatever. These are NOT "clean room" sites.
More pronounced than most and you captured it well, but I'm going with struck through grease or impacted debris.