and yet 97% of people (according to golds pole) have not personally heard of anyone whose tank has gone thru bulkhead or injured someone apparently.......
you'd have thought it would be higher with the amount of cowboys like me out there with our straps.....
And you think 57 people that never heard of any accident involving water tanks is a good size test sample group to risk your live for, with simple physics that can't be disputed working 100% against you. Seriously? 
it's definitely by no means conclusive. and even if it was 500 people, it still wouldn't be conclusive. a test (or several) in varying test environments where a load is up against the bulkhead and 'better' restrained than what is shown in ionics etc video would be conclusive.
I know personally a whole heap of window cleaners. I also know of quite a few who have had accidents, some big enough to 'write off' their vehicle. yet none of them got injured or killed by their tanks. this, too, isn't proof. but my reasoning is that surely more people would have known some more ppl injured in this mini poll.
for sure having a load properly secured is safer than the huge question mark over bulkhead integrity, tie down points, bungees (!) etc. No doubting it! but I feel perhaps there is a certain amount of scaremainering also. that or maybe everyone has been lucky and not had big enough smashes with enough water on board!
the likes of ionics etc would have a lot more converts to professionally fitted systems if their test was slightly more realistic, i.e. better secured, against the bulkhead....... as opposed to all I've seen on these tests so far. that being said it's on my to do list once I've collected my new tank tomorrow. don't know what that says ....that I agree it's got to be safer?!