Yes, there has been accidents because of this.
"I understood that the sky pointer concept makes it easier to return to level flight.
and that is the most important thing...the recovery"
Well if you read the findings you will see that this is not the case.
If you believe the report the recovery was 5 times WORSE with the commercial ADI. Here is a quote from the actual report
"While recovery on the military and General Aviation ADI was roughly similar, immediately
obvious was the inferior performance on the commercial ADI—ironically the ADI currently
used by all pilots tested. One pilot even made 100% roll reversal errors with the commercial ADI, and subsequent probing revealed that any misunderstanding was not the reason for his
performance."
Also
"Discussion
Roll reversal errors on the commercial ADI were almost 5 times more frequent than on the other two ADI's. Since there were no significant differences in response latency across the three different ADI presentations, pilots do not appear to engage in a speed-accuracy trade-off (cf.Gardner, 1954). That is, the much higher probability of roll reversal on the commercial ADI's
is not preceded by a faster response time when faced with a commercial ADI presentation, which means the higher error rate stems from other sources. This large performance gradient, by pilots who actually use the commercial ADI in their daily practice, would point to the importance of the control-display compatibility principle in using the roll index for directing
recovery action. Indeed, this result mimics the findings by Kovalenko (1991), that no amount of overlearning (all pilots tested in our study had a minimum of five years commercial ADI experience) can likely overcome the inherent incompatibility between required control action and display movement in the commercial ADI."
I find this very interesting. I can recommend that you read the report. It's not so long.