I am surprised that they say, alcohol was consumed but it did not affect the ability of the pilot” that is quite a lenient statement!
That part of the investigation findings is almost certainly a major input into the causes of the crash. When you have consumed even a small amount of alcohol, your judgement of distances and clearances is impaired - and you are going to need all of your judgement to be top-class, if you choose to skim the surface of water at a very low height, and at speed.
Add in the sun glare (direction and low angle), possible distractions involved by pointing out features of the property (by either seller or buyer) - and you have all the "holes in the cheese lining up".
I'm not so sure that the pax weight factor was a large input factor into the crash, but the high level payload, possibly did have some additional part to play. If it was a prominent factor, I'm sure it would have been mentioned in the investigation.
The bottom line is, if you want to fly very low, you are seriously narrowing your envelope of safety margins.