A couple of rebolted routes at Mountain Quarry from a few years ago had their bolts recessed a tad too much. If you use older style, fatter karabiners then they will not hang freely against the rock and may well fail like the one in the link above. Using skinny ones that can fit and turn easily between the bolt and rock will solve this problem.
Good thread, Neil. Not something that all bolters would think of…..the prevailing wisdom seems to be to recess a lot with the philosohy that “if recessing a bit is good, then really sinking it in is better…..”.