Well here's what we found.
The cylinder that lost the lock. valve had hit the piston (lightly none the less hit)
It was discovered the driver had trouble with shifting (shifter jam) he stayed in it
Data shows it hit 8500 rpm . So the root and cause all comes to light. Suprisingly there was no cylinder wall damage .it was a good catch by the cars owner to remove the oil pan.....ty all for you input!