Geoffers......an evaluation tool I used in the aircraft and sim when doing IF training, was to announce "Unusual Attitude Recovery".....and set up the exercise with the usual...."Right...Head down...eyes closed....I'll fly....you keep yer eyes closed till I tell you to take the controls...then you take control and recover from whatever attitude you are given. (...or words to that effect)
Once the Stude got his head down and eyes closed....I reached across and adjusted his Attitude Indicator to show a Ten degree Bank when actually level.
Then....do the old whoopsy doodle bit for a minute moving all the controls around and wiggling the pedals.....then in a fairly benign aircraft attitude....give control to the Stude....and watch the next few minutes of fun.
What I found.....those that knew how to actually fly the instruments....tweaked to the attitude indicator roll problem in very short order.....and those....usually the great majority would never figure it out. We flopped from one side to the other as they fought heading problems over and over and over.....all the while ignoring the Standby and Co-Pilots Attitude Indicators that were both showing something different than the one he was using.
What that showed was whether the guy was flying instruments (plural usage on purpose) or the Attitude Indicator.
In just a couple of words....."Cross Check".
Remember my complaint about Check Airman from a Company Checking their Check Airman Buddy....rather than having a third party do the checks and the risk that poses?