Engine-out scenario and turn& slip cue... (Critical engine failure)

I continue to enjoy the excellent flight dynamics on this Q-400.

One of the tests I have run was a critical engine failure. 

I killed my left engine. Prop autofeather was engaged. After a while I noticed the turn & slip cue had the slip bar displaced to the left ( same side of the failled engine ) instead of to the right as it should.

Sometimes I was able to get a slight right displacement, but as soon as I used even the slightest right rudder / rudder trim input, the slip indicator would move to the left.

I believe that with the aircraft trimmed for wings level, actually a bit of right ( good engine ) wing down, there shouldn't be a displacement of the sideslip bar to the left?

In the attached picture I am flying with my left engine stopped, the right being at "full rpm" ( right condition full ahead ), and the throttle around 66%. I am using only the ypke to counter the prop and engine-out effect and the sideslip is prcatlically inexistent. Just a slight push on my right rudder and the cue will indicate that I need left rudder...

Yet another detail, which I really do not know it the real thing also has :-)   The barber pole on the speed tape does not adapt to bank. Shouldn't it "grow" up when on a tight turn, indicating the higher stall speed margin limit accordingly?

EDIT: Thinking about this, and debating with Alec, he suggested that a possible reason for the less yaw and thus need for rudder input may be related to the fact that this aircraft hs spoilerons. When the yoke is turned left, they are raised on the left wing, and thus tend to help compensating the otherwise more pronnounced sideslip (?)

Q-400, Left engine stopped, right engine at FULL RPM and 66% THR. Only yoke ( right ) being used - Y/D disconnected!