The article mentions the app misleading him into believing he had incurred the debt, but never goes into how it was misleading. Was he actually in that amount of debt, or was he misled? If he was in that level of debt, was he misled about the risks he was taking?
I'm not a fan of the argument "they shouldn't have let him make decisions he didn't understand" because I believe the onus is on us to know what we are doing before we do it, and arguments like these are what led us to our current regulatory framework disallowing investors into markets unless they meet capital requirements, essentially pricing everyone but rich people out of markets.