I wouldn't even call it mislead, there were just outright lies.
Rather than having people on the Internet get into a boring flame war ("It's a lie!", "No it's not!"), I want the courts involved in the process...to decide what are and are not material statements, and exactly how much damage did Sean's quotes cause to the plaintiffs (if it actually caused damage). The problem seems to be that lawsuits are expensive and can take a lot of effort for very little benefit. And there's no guarantee that the plaintiffs would have a "slam-dunk case" here.
I don't know if a court can charge someone with lying about a game (maybe false advertising but that sounds like there are technicalities for that specific charge), but you don't need a court to look at the ridiculously long list of things that Sean directly said were going to be in it, and weren't, to realize that he was just lying. The only other possible argument would be that he said what he wanted to game to be, but there is still a difference between "Yes you will be able to do that in the game" and "That's what we are aiming for".
According to this bloke: https://www.youtube.com/watch?v=Jz1oFNUZ-P0
It's illegal in the UK, where Hello Games is.
I'm not a lawyer so...
If you watch back over the videos (it's actually quite interesting to do so) you can hear that he never makes any actual promises about things being in that weren't, other than with multiplayer. Everything else is stated very loosely and without any specifics ("you'll be able to do that kind of thing"), and most of the stuff he's said is broadly included, just in a vastly watered down form.
So the only real concrete claim that he's lied on is multiplayer, and he can just say 'oh it's supposed to be in, but we've been having technical difficulties' and it would be hard to prove otherwise. Yeah, you can point to the lack of models and whatever, but he can say 'well we were going to represent everyone as just a big textbox saying 'playername' and there's not a lot you can do.
Not to say I agree, it's always frustrated me that games are treated as somehow a special type of product. If you bought any other product and it didn't work or kept on messing up you could, and would, return it immediately. Games get treated as though game breaking bugs and unplayability are somehow ok.