Seriously, is there any helicopter that you know of or have flown that would not have provided sufficient margin under those conditions? And no corner cases like it was a hurricane or something. Just a plain old nice flying day like they had.
No, simply because we operated with a minimum of a 10% thrust margin whenever possible, especially for high power scenarios like confined areas, mountain flying and any OGE hovering.
You can calculate your thrust margin by looking at the max weight on your OGE graph - for them 2500lbs and reducing that by 10% - ie 250lbs which is 120 lbs lighter than he was at the time of the accident.
His DA was around 1200' given the temp and elevation so he was further up the graph than you imply.
The example in the R44 POH of weight and balance shows full fuel isn't available with 3 POB and a small amount of kit - how much baggage would they have for a fishing trip? And the example uses 170 lbs per pax which is light by anyone's estimation, especially in outdoor gear.
Given the layout of the HLS and the wind direction he should actually have had a reasonably clean airflow, certainly above the treetops even though the report cites mechanical turbulence from the low buildings and the trees (with a max estimated of 20 kts, I feel this is unlikely.
Not sure why you think the yaw induced panic could have happened anywhere on the trip - the proximity of the trees was what seemed to panic him.