Automatic pool rollback is for when the labels disagree, and is a standard cross-platform zfs feature, although there may be additional heuristics and mechanisms in the ZEVO port. It is a gentler form of zpool -F.
There is some discussion here :
http://www.c0t0d0s0.org/archives/6071-N ... -fsck.htmlDon't confuse pool rollback with dataset rollback (zfs rollback snapshotname).
The problem in the discussion you link to is that there is a fully consistent filesystem that nevertheless contains a bad object; rolling back a few TXGs at import time *MAY* have decommitted the bad ZAP DMU object, but it also likely would have decommitted other (possibly good and important) data at the same time. If the label txg values agree, it is almost never a good idea to roll back to previous txgs at import, especially not without involving an operator.