Suppose you think reasons are facts. I'm thinking of normative or guiding reasons, not motivating or explanatory reasons. Consider the following objections:
On the assumption that reasons are facts, we can have no false reasons and we have no reasons for any of our false beliefs. Yet, we know both that we have (and have had) many false beliefs (e.g., that there can be justified false beliefs!). To say that there are no false, justified beliefs at face value is to accept the absurd consequence that none of the false beliefs we hold are held rationally, since they are not capable of any justification whatsoever. Further, since we often cannot tell with any certainty which of our beliefs are true (their being a certain degree of opacity to the matter) we must be sceptics about most, if not all, of our beliefs. Since we can’t be certain that they’re true, we can’t have any justification for them whatsoever, and further there’s no difference between being rational and being irrational (being epistemically responsible and irresponsible) so long as we’re mistaken.
It's true that if reasons are facts, there cannot be false reasons understood as normative reasons but that does not entail that we have no reasons for any of our false beliefs. This is a point familiar from Williamson. If E = K, what justifies must be true but it doesn't follow that what is justified must be true.
Of course, I do think that there are no false, justified beliefs. To the extent that a false belief is supported things we know to be true, it is capable of some degree of justification, but that's perfectly compatible with my claim that they will not be permissibly held/justified. Moreover, to say that there are no false, justified beliefs is _NOT_ to say that no false beliefs are held rationally. The reasonable and the rational and the responsible is often taken to be distinct from the permissible and the justified. Rationality is a necessary condition for certain kinds of excuses (including mistaken belief excuses for action), but excuses do not provide justification. Rational/reasonable response to reasons is not the same as the justified response.
Suppose we cannot tell with certainty which of our beliefs are true. Okay. Suppose certainty isn't needed for knowledge. If we identify justified beliefs with items of knowledge (as Sutton does), there can be no false, justified beliefs but we can have justified beliefs without certainty.
Also, the claim that there cannot be false, justified beliefs is not incompatible with the claim that there can be defeasibly justified beliefs. Suppose that we identify justified beliefs with items of knowledge. If knowledge can be had on defeasible grounds, the same goes for justified belief. Both, however, would be factive. Now, start subtracting conditions away from knowledge while holding the truth requirement for justified belief and you won't then end up with a view on which justifiably believing p requires indefeasible justification.