Lee: just tried to follow your recipe for spicy salmon and it was an epic fail.
David: Why?
Lee: it's overcooked
David: Mmmmm... that's weird
Lee: Nope, i have to be honest though, i didn't follow the recipe *exactly* as you gave it to me.
David: that explains it!
Lee overcooked the salmon, because he did not follow the David's recipe precisely.