The laptop did shutdown and "EpePc has been corrupted (error 92)" showed up. I restarted decryption process and turned out to be ok. So I answer my own question
Were you using a WinPE CD? If so the corruption was because you forgot to offline the disk before starting.
Yes I used WinPE. How do I offline the disk?
Using the diskpart command from a shell. There's a thread here if you search, I can't find it fom my iPad interface though.
Duh. Too much jetlag :-)
This info should be in the pe guide which shipped with 6.2? It was not in previous versions because they predate pe3.01 which is when (AFAIK) Microsoft introduced this funky behavior.