I believe this was near Stanley, Idaho. Elevation is 6,500'.... I do not know what the temp was at the time of the crash, but even at a moderate 80F, density altitude would be over 9,000'.
If that wasn't enough of a clue, the rule is you have at least 70% of flying speed by the time you reach 50% of your takeoff run or you abort
If that wasn't enough of a clue, the 20 foot per minute climb might've caught his attention.
I generally don't like to make assumptions about other pilots, but this guy was an idiot.