GPT 4 says that the student was late. If you look at the sentence objectively, then the best interpretation is that the submission was late, not that the "professor turned up late", since essays are typically reviewed over multiple days, not at a specific date and time where lateness of the reviewer might be a factor.

Sometimes GPT 4 says that the sentence is ambiguous, but as I explained above, it isn't really, but that takes a lot of understanding of the review process.