From what i understand, deda round up to 31.7 and everybody else rounds down to 31.6 but the size is essentially the same.
I also have a set of presa bars with a f109 attached. torqued just past 5nm, it did not make any marks like that.
If it was crushed, you would know. Carbon doesn't bend or relax, it's either structurally sound or it fails, there is no in-between.
If it's just the thick-ass paint being marred, which is the case, you wouldn't notice a difference in the bars.
Unfortunately for the OP this doesnt really reflect reality, it would be nice if it did. Being a composite material, it doesnt behave like a metal, ceramic or plastic, and it can fail in different ways. It doesnt have a plastic region like metals, but it also doesnt elastically deform linearly to a failure point like a ceramic. Carbon definitely does bend, look at a windsurfing mast for instance. It is possible for an area of the component to be damaged, with the rest of the structure holding it more or less in place until the damage propogates far enough for it it give completely. When someone breaks a bar (or any other component), chances are that it suffered some kind of damage at one point without the owner knowing. It held together fine for a while, until they ran over a bump or something, and gave it enough load for it to snap. Point is, there is definitely an in-between.
I wouldnt ride it. But its your bar so its your call.