slacktide
"It was mentioned earlier in the thread, but to prevent rehashing the issue, the hollow pivot bolt necks down internally and can accept the lockpin fairly snugly.
But - the 777 has this exact same configuration, with a hollow pivot bolt right next to the lockpin location. (Sorry, can't find a good photo online.) I'm curious why this has not been an enough of an endemic issue on the 777 to issue an AD. There have certainly been inadvertent 777 nose gear retractions that you can find on Google."
The gear pin is a bog-standard pip pin that any engineer from the last 50 years or more would recognise. It is indeed the same part number for the 777 and 787:
Judging from the photo of the nose bay, I suspect that a "snug fit" inside the (larger diameter) pivot bolt would only occur if the pin were inserted up to and including the shoulder.
It would (should?) then be obvious to the user that the pips were not engaged with anything and that the pin could be pulled out without having to depress the button to release it.
While I agree that it's not 100.00% Murphy-proof, any engineer or ground handler who doesn't understand something so basic is in the wrong job.
(with the caveat that the "pin in the wrong hole" scenario just a theory so far and has yet to be confirmed by the AAIB)