There's actually no truth at all at what you've said here: none of your post applies to the video, unless you were responding to someone else.
Since you're calling me a liar, I decided to not only re-watch it, but googled the UK regs and looked for other complaints searching for a pattern that would support his claims, and yours.
From 1:00 to about 1:40 he blames INEOS. He admits he bought the truck and it seems he assumed that having back seats voided some or all of the UK's commercial spec regulations, (which have differing tiggers and restrictions than in the US). It seems that's not the case. He is insinuating it was INEOS's responsibility to tell him as much. Should you take the time to google it, there a ton of differing rules in the UK regarding commercial/passenger trucks they don't have here... but like here, its up to the buyer to know them... How is that INEOS's fault? Should they have had klaxons and a flashing warning sign that says... "If you are specing the cheaper commercial truck, and adding optional rear seats, you're not going to get away with ignoring commercial regulations, we're on to you!!!". In addition, I'm not seeing anyone else on any boards having made the same mistake. I am seeing people discussing the use and limits of the spec, and if its worth it though, so apparently this isn't some secret.
Anecdotally, I've also purchased many commercial trucks for our business, and not once has the dealer or manufacturer asked me my purpose or if I knew the laws regarding the GVWR of the trucks. They sort of assumed that if i'm inquiring about an f650, I know I want and what the driver requirements are for an f650. They're just interested in depositing my check.
He didn't know the law, he didn't take his time to look into it, he made an assumption so It's his fault, and only his fault.
I'll add: It looks to me like the regs put this as being able to travel posted limit on what we call a highway, and a ceiling of 60mph on regular non interstate primary or secondary roads... which oddly is within the MPH limitations on every road I've traveled in the US. I have no recollection of any primary or secondary roads that I've been on being 65mph (out west maybe?). My UK drive time can be measured in weeks, so it's not extensive, but, once again, there aren't a ton of roads that it would ceiling out on because of it's limitation. The other comments I saw on defender discussions followed the theme of... No one is looking for defenders registered as commercial (no passenger) and pulling them over. In other words, they cant tell the spec from the outside.
Since I now wasted my time on your accusation, here's where I
will speculate. I originally assumed the trim quibbling was more about him ordering the wrong model, but it really does appear the speed limitation is much ado about nothing. I was just in the UK in an AMG and I barely found places outside of the motorway where I could go over 50. I'm now thinking the real reason is the only other subject that seemed to bug him. The cost. The unseen fit issues didn't suit his image for the $ outlay, and he was really happy he didn't sell at a loss. I now think this is someone with buyers remorse pinning everything but his emotions for spending too much.