OVERWEIGHT - NOT
You keep going on and on about AKD being overweight. Yet you do no research, ask no questions, put in no effort. Have you flown out of this airstrip or are you calculating your posts from your armchair? It is a fair question when you are potentially damaging someones reputation.
This is what I have found out.
This careful pilot did not get to his advanced age by being an idiot. I have been told he flew in the Delta before. So unfamiliarity would not be an issue.
The aircraft was equipped with an ADAS system (see what you can find out if you put in some effort), therefore its engine history is known. The engine was installed in mid 2009 (as I was told) so not exceptionally old.
Now for your weight issue
This aircraft was equipped with an APE II conversion. For the naive this means the aircraft's MAUW for take-off was 9062 lbs. It did not have an APE III or APE STOL conversions installed (look it up).
I have been told by two pilots in Maun that Martin called 3 hours fuel on departure. Depending on the company's operating parameters that would put his fuel in the 900-930 lbs area. After he burned roughly 300-330 lbs (for the 1:15 flight), that would give him about 600 lbs fuel.
I was told he was then flying to Pom Pom (20 min) and back to Maun 20 min.
Now calculate your weight and balances, satisfy yourself that the aircraft was not overweight and please stop slinging mud.