There are some big chunks of the pistons missing which certainly points to detonation as it looks like the motor beat itself to death. There is also some scorching and scuffing but there are many things that could have happened. Was the tune too aggressive and did the car run too lean? Was methanol distribution uneven and is that why some pistons look far worse than others? Not enough octane and continuous detonation? Faulty parts? Was the limit of these internals reached and surpassed?
There are a million ways to spin this and this is not an indictment of Vishnu's tuning on the N54 although Vishnu's influence in N54 tuning has waned to the point of irrelevance. This is to educate that failures do indeed happen, everything has a limit, and as N54's with single turbos become more popular pushing the power output to well over double what the motor has from the factory means the margin for error becomes far smaller.
Thank you to the owner for sharing these pictures and not hiding them.