The problem is that a fish will have many many more combos of K9 and 89 than a reg will. A reg might only have 89ss here as two pairs, while a fish will have all K9o and 89o.

check back and re-eval river for sure. If he checks again, I'd prob shove on river for value and expect him to have some weird Kx or K8 even. If he shoves into us on river I'd prob fold.