This is a tremendous tragedy for you tuck and I'm indeed sorry for the hassle your going through, at least you didn't get hurt.
As a Cert Fabricator, Metals Technician, Welding Inspector, Technology Instructor and avid camper dude; there's alot to look at here.
I would be very surprised if there isn't pile of data supporting the jacks there design constraints and capabilities, lift conditions and life term. the design would most likely have gone through some sort of destructive test analysis prior to production and I would assume that on going inspection happens at the factory.
Having said all of that errors still happen, particularily if 100% inspection is not done, by the way non of us could afford jacks that where inspected 100%, current costs for something like that would be around $1,200.00/jack for xray and die pen testing.
I have had a similar but less tragic issue with my first 10.6 Bigfoot. The lower weld on the front right Happijac developed a Crater crack due to the loading stress and direction of weldment. I caught it through visual inspection which is something we can all do. I rewelded it and she was fine.
On my next camper 9.0 Artic Fox, the swing out bracket for the dually did not engage in the open position and slipped once the camper was ready in the air, just as I started to move the truck forward the support was gone which was holding the camper in position and luckily I noticed what was happening before going much further.
On my present camper 10.11c Bigfoot I recently noitced the swing out bracket on the front right is slightly bent. this could also contribute to a non vertical axis of lift, again a corrected the deflection but technically once a paper clip is rebent it has lost some of its' design strength and ductility, the next failure will be abrupt, solution new brackets must be purchased after any slight bend or twist.
Because these jacks hangout in the open they can be snagged on all kinds of things, I've dragged mine through snow, overhanging branches in the bush and even caught the camper bottom slightly as I pulled out because I didn't pull it up high enough, particularily due to my Dodge having such a high set back end it can be tricky. Another thing which can add to the deflection issue is wind and movement over time, have a look at all those campers sitting on lots all over NA just on their jacks alone. Remember the paper clip, it will do its' job just fine for a period of time but given enough load and workability and sooner or later you will disgard it for a new one.
1.Regular inspection in line with any commercial rigging requirement is a must
, keep in mind just because we have remotes cord or cordless we can tend to get complacent, we're still lifting an avg of 3000lbs or more for the vast majority of us. there ain't a rigger or crane operator out there worth there salt that wouldn't inspect heavilyprior to lift.
2. Always block when off the truck.[/i]I know some manufacturers suggest it's okay to leave these little legs supporting the weight of the rig, but how old is the paperclip and how much stress have you put it through???
3.[i] Always employ a spotter to observe the camper from a safe distance for issues arising as you lift
, pull out or back under. Sometimes stuff happens that the driver can't see from their perspective. This is the easiest way to distort a jack or two, again spoken from personal experience.
Hind sight is always twenty twenty after the fact, bottom line lets use this example to improve the way we manage the load/un load process. stay safe and out of harms way.
As for specifics on what went wrong here, I believe that's an issue for adjusters and not arm chair quarterbacks. One thing is for sure Tuck you have a very large audience watching how this issue is resolved by lance.