I've read your post a few times but find it difficult to determine exactly what's happening. However, without a doubt, although you might find it unavoidable to "abruptly shutdown" the cluster, for scsi3 LUNs this is bad news.
In scsi2 reserve/release the reservation(s) are cleared with a scsi reset (ie, a reboot) but in scsi3 the reservations are persistent and survive a reboot. Therefore such reservations need to be cleared somehow.
Read this:
Sun Cluster: Cluster Reservations and Quorum
I cannot be sure that this is your issue but "abruptly" shutting down a cluster with scsi3 LUNs should be avoided if at all possible.