This is an aircraft with an aileron rudder interconnect, left still operational in this machine. Many folk disabled this - it can be overridden but presumably would be felt as pressure on the controls. With only 27 hours on type at the time of accident, it's possible the pilot hadn't previously found this to be an issue. At the flare, with possible, turbulence and crosswind, the use of aileron and rudder are not likely to be co-ordinated, (especially when I fly) so this system will be adding adverse pressures. Not what you really need ; a time when it's important to make the aircraft do what you want, not what it wants !
As for the estimate of turbulence impacts dissipating within 5-8 time rotor diameter, I'd really like to see the link to that, or some citation, please. Intriguing. It may be true in some ideal conditions, but certainly isn't true where I often fly. We have a windfarm a couple of miles upwind - for the prevailing wind, and it can be impressively rough if you pass through the direct wind track on climb out. I am certainly well outside the 8 lengths of the turbine blades distance !