I was fastening Shimano STI levers onto Bontrager carbon drop handlebars yesterday, with my torque wrench set at ~2nm, and heard a short rather loud click/snap sound shortly after starting to tighten, probably well below 2nm at that point. I took the levers off, and inspected the area by shining a flash light on it and looking through a magnifying loupe, and also tapped the area with an allen key to see if there was any change in sound. It looks and sounds fine.
If not necessary I'd prefer not to throw them away, but I also don't want to take any big risks. Does it sound like my bars are a write-off?