While One Hand and Shield Ulti Shield wall is running you are immune to DK Skill Fossilize and likely other unblokable stuns too. While opponets shield wall ulti was running my Fossilize skill was greyed out, so i couldnt target or use fossilize, although opponent had not the "circles" around him, indicating he was cc immune at that time. I guess you are just CC immune while you run Shield Wall Ulti, which is not intended and shouldnt be the case for unblockable stuns. Observed in EU no-cp Ravenwatch Campaign. Thank you!
PC/EU
Starstréam - NB, Loveknight - HybridDK (4*), Stahlstrahlenreiter - StamDen, Azgul Grahl Bashrugk - HybridSorc (5*), Tínúvíél - StamCro, Thógard - StamPlar