Distracted flying   

It's intersting the speculation that this website puts out - 

"We suspect this may be just civil time as the pilot is a former USMC squadron commander."

"The closing remarks in the pilot’s statement might make some readers suspect they were intended to reduce the chances the NTSB might examine the organisation deeper and wonder if their had been any prior collusion on the statement’s contents or whether it reflected the thrust of initial investigative interviews."

Heck, the pilot says it himself - he flew it into the trees.  Very cut and dry.