I would be curious to know if you got any response from Oracle and/or Netapp on this issue.
In my case I am using Oracle 11.2.0.3
I am running into the same problem while trying to set up test databases on our brand new Netapp.
I must say I'm disappointed with Netapp that they don't stay more current.
Although I have not verified whether or not I have the same exact wait condition, it does happen
regardless of whether or not DNFS is enabled.
I haven't been able to get an rman 'restore controlfile from '<path>'' to work -- it just hangs.
The source disk is not Netapp but the target is an nfs volume.
I did not have an issue restoring to a netapp Fiber Channel volume.