You are right, it might work. I thought the narrative jumped forward four years after Szeth killed Gavilar, not five, so yeah, it could work. Furthermore, after the first chapter, the narrative jumped forward 8 more months.
I am reading The Way of Kings and on the page 481 I noticed this quote:
The problem is, this quote is from chapter 31 which is from Kaladin's point of view 6 years ago.
As far as I know, the Vengence Pact wasn't established yet and Gavilar was still alive at that time.
So my question is, is there an error in the book or is there something I don't understand correctly?