Yeah, James Cameron has been to the Titanic and back 33 times. And to the Mariana Trench, and who knows where else. It's not impossible to do it safely, but that requires spending money on the correct materials, listening to your engineers, cross checking with third party engineers, and not rushing things. Carbon fiber is a stupid material for a sub hull, using different materials with different expansion and contraction rates for your pressure vessel is a stupid decision, not having a way for the passengers to self-rescue is stupid, using a wireless controller without (multiple) hardwired backups is stupid.

The entire thing reeks of a CEO who doesn't want to take the time to do things properly in fear of investors losing interest. And I get that fear, I work for a small company as well (not building submarines) and you do have to move quickly with a lot of things. But you DON'T rush things when human safety is a factor.

That sub should have been remotely operated dozens of times and gone through multiple iterations before they ever let a living creature inside it. It should have been x-rayed between every dive to find microfractures in the brittle carbon fiber hull. Multiple prototypes should have been built and extensively tested to find flaws in the design or assembly process.