While in 2008 central banks had to bail out the banks, this time they had to bail out a number of financial markets. Some of this may have been inevitable given the enormity of the economic shock. But weaknesses in the non-banking part of the financial system made matters worse. The FSB carried out a thorough review of the March market turmoil.
It was published last November and I recommend you read it. As the review showed, liquidity mismatch, interconnectedness, and sudden changes in expectations, those systemic risk factors that I mentioned earlier, again played a key role in propagating the initial shock.