Regarding gyro side-slips in general, and not specifically with reference to this accident:
I have long enjoyed (not NEEDED, just enjoyed) slipping gyros. My mentors in the PRA Chapter 24 (Ron Menzie was one) did them in their Bensens way back in the day.
At one little airport that used to host an annual U.L. flyin hereabouts, there was often a gentle cross-wind from a sea breeze. It was possible to do a slow approach in the open-frame Air Command, slipping so that the nose pointed into the wind and across the runway, until you finally kicked around at about 75 feet and landed. In a stronger breeze, it was also fun to fly a small rectangular ground path in the Dominator, with the nose continually pointed into the wind, and the crosswind legs accomplished by slipping first one way, and then the other.
Once, a student of mine, who had FW experience, just about STOOD on one pedal of the Dominator at about 75 mph IAS. I was in the back seat. The roar of wind, sideways past my face and helmet, was impressive.
Please don't try any of this in a gyro with a low-slung open "tub" or enclosed pod body, unless it's been tested and passed for such shenanigans.
None of this slipping nonsense is necessary, of course. In a sport aircraft, however, fun is the mission. I believe that the designer should not tolerate avoidable coffin corners, just as a Pitts Special should not be so designed that you can't recover from a spin. Yes, you could placard the Pitts against spins, then fold your arms after the crash and say "I told you so." Is that really a satisfactory solution, though, in a "play" aircraft?
Proverse slip-roll coupling is not that hard to design out of a gyro. IMHO, this designing-out should be done, and verified by testing.