I figured this would've been something he'd have seen happen in similar trades? Who, knows maybe dude went full r-tard on this 1st attempt; he's 20 after all.
This may have been his first foray into trading credit spreads. The article said he only started trading in March. He probably did well buying calls, and then "did additional research" and found someone on youtube or stocktwits or wherever saying he could make an easy weekly paycheck selling bull credit spreads because the market only goes up. I think Robinhood showed the debit for the cash to purchase the shares without showing the shares. His suicide noted indicated that he understood the actual risk involved and was therefore angry and at a loss to explain how it appeared he had lost so much more than the few hundred he thought he had at risk.
I'm not assigning RH any culpability at this point, but I am not going to blame the kid either. But if I do understand the situation correctly, RH wouldn't want me on the jury.