Although it is certainly challenging, you shouldn't spend only an hour reviewing a 3,000 LoC review, unless most of it is trivial refactoring, especially if that code is security-critical and handles untrusted input. That's only 1.2s per line of code. No chance you have good quality control with that amount of attention.

If it's taken someone a whole fortnight to write it, you should expect to spend at least half a day reviewing it, IMO.