I wrote 'finishing': the pin is already in the outer links fully and one can no longer miss. I've had occasions when I couldn't get the pin inserted perfectly, the smallest turn of the chain-tool that would move the pin would move it too far - perhaps there was something wrong with the feeling in my fingers, but I didn't think so. (I re-used pins: this may have been the problem. It also could have been a failing chain-tool: I've broken a few.) When this is the case a vise-grip can even it out. It now looks as though this guy merely didn't install his special link correctly, a different problem.