Quite a few macroeconomists have said the Fed caused or depeened the recession: http://bruegel.org/2016/02/blaming-the-fed-for-the-great-rec...

But it's also a bit philosophical, because any causal claim implicitly invokes a counterfactual. Like, if a bus drives off a cliff, was it the fault of the cliff or the bus driver who didn't respond quickly enough in trying to steer away? To me, common sense says that sometimes it's the cliff's fault and sometimes it's the driver's fault - the difference depends on how early the driver 'should' have known.