Certainly it's not very wholesome design practice to leave open the possibility of the rotor contacting the prop.
However, the deeper question is what the heck the rotor was doing back at that extreme angle in the first place. To make contact. the rotor has to be at the aft control stop and flapped back to, or near, the teeter stops. The only time we normally see this is when starting the rotor on takeoff with low RRPM, stick all the way back and the rotor in retreating-blade stall (so-called ground flapping).
It's most likely that the rotor-prop contact in flight was the result of a PPO, During PPO, the gyro's body pitches forward violently, the rotor cannot follow the resulting spindle-forward cyclic pitch input, and the rotor experiences retreating-blade stall -- like a ground flap, except it's invariably fatal when it happens at altitude. This can happen even to gyros that have positive rotor-prop clearance at full-flap-back.
Such PPO accidents (in vulnerable machines) quite commonly occur when the gyro rolls out of a pattern turn. The pilot feels a little ballooning action from the higher RRPM that the turn caused, and bumps the stick forward to "correct."
This happened countless times in the bad old days of homebuilt gyroing. Among the vulnerable brands (in addition to the RAF) are early Air Commands, Bensens, Brocks, and Parsons and Snowbird tandems.
The PPO problem has been designed out of most newer gyros, but unmodified gyros from the 1980's and before still have this dangerous flaw.