Taken at face value, this advice boils down to never doing anything that involves a large risk. No civil rights movement, no D-Day invasions, etc.
There's certainly a reminder here about tail risk, and the ability of the market to stay irrational longer than you can stay solvent. However, the takeaway isn't "only take on big risks if failure is impossible." Taking calculated risks is an important life skill, and so is realizing that humans have pretty bad intuitions about risk.
In hindsight, we may find some funds that had 30 different short positions similar to this one. This one position blew up badly, but if the others come out moderately ahead, and they came out ahead net-net, then maybe this just validates their strategy.