Depends.
Say you are trading a luxury to some civ. Then, perhaps with a little motivational action from you

, your trading partner gets fed up and attacks you. In this case your rep is fine.
Same thing, you are trading a luxury to some civ. Only this time, a barb ship sits on the trade route at a bottleneck where the route is only one tile wide. Or a third-party civ attacks your trading partner and pillages the road connection to your lands. Or a volcano blows up in neutral territory and your nearby road gets Pompeii-ed. Tough luck mate, you just busted your trade rep.