So i've taken a look into this, and it seems to be an issue which strangely is only happening on mirror mode. For some reason, the game IDs are not updating quickly enough which is causing the script to think that the rock is still unmined. I will raise this issue with the devs, though it might be an inherent limitation of mirror mode. For now, I would highly recommend switching over to Stealth Injection, where the script should run completely smoothly.
While I was looking at the code today, I also spotted some slight performance bottlenecks which I have now removed. You should see a slight performance improvement when running the script going forwards.
Cheers,
Apa