Well, a government intervention would be through QE, providing stimulus for SMEs and support for major players etc. There are quite a number of downsides to this; Inflation notably. This would have a domino effect, the value of cash would be reduced and people who have them stashed up in savings' accounts gets poorer. Assets would also spike in price.
This could also create an unequal market, and create a design that would shortchange some businesses. These would further adversely affect the economy and the recovery process would be slow.

On the flip side letting the market operate freely, would leave the economy stagnant for a period of time. Spendings would remain low and businesses would lose out, I can't tell how long it would take for the market to recover.

In my opinion, both scenarios would lead to a slow economic recovery. Only one would leave the market less regulated by the government.