atf: What if the two were unrelated and coincidental? Armed with info on the second load, I am wondering if they are seperate causes?
You have definately gone through all the right steps to solve the issue, so the suggestions below are more as a result of ponderings because you havent indicated the depth of your testing, rather than any questioning of your analysis: so forgive me if it sounds otherwise.
The pick up still seems like rollout, but I would have to see the hook design first - some are protected against rollout). This can sometimes be caused by other things than eye size, and it is sometimes possible to use the sling to assist in rollout, but very unlikely. Also, I have seen one or two people achieve a rollout where many others tried to replicate it and failed, believing that it could not be done. The reason I am thinking rollout is that the hook was firmly closed when you inspected it. I know that it could flick shut after an inadvertant release, but during the pick up I am wondering about how much load was applied - though you do say 100% TQ.
On the put down - I know you have checked, but the release cable can always be a suspect, even if it appears to be of sufficient length. Test it's rigidity with a heavy load on, and then see what happens with a bit of load movement.
Good luck. We would love to hear the outcome if you find one.
