Detonation can definitely cause the damage you saw, but that would be my second most likely event after FOD.  To get detonation you would have to have not checked your timing very well AND gone to nearly full power.

That turbo is very similar to mine.  I wish I had a larger A/R but .81 is adequate and worked for me to make over 300hp at Reno.  But even then I was still not using full throttle.  I set a limit of 45 inches for Reno.  My normal limit is 40 inches for take off (and that is short periods only).  I currently have the waste gate removed and the turbo will only do about 38 inches at sea level..  which is perfect for the RV and keeps a rein on my lead-foot (or fist).