There is a bit of an issue with C206's that not many people who fly them seem to remember.
If you have less than 1/4 in a tank, any sustained turn for longer than 1min can lead to fuel starvation. A nice slow decent from the drop height circling over the field, issue wouldn't present itself until feeding in power again.
There have been a few accidents where after the aircraft has been retrieved and engine bench tested, it has been found to be running with no issues. The pilots have then sworn until they are blue in the face that they had fuel in both tanks.
Also been a few cases where the boys have run a tank dry as well
Just a theory anyway....