See the NTSB report, it spells it out pretty well.
not really - it lists some actions the Passadena PD have taken and suggested 4 changes
As a result of the evaluation, the following actions were identified that would enhance heliport safety, and bring the facility into conformance with current heliport design standards (Advisory Circular Heliport Design AC 150/5390-2C dated April 24, 2012).
1. Recommend trimming of a 38-foot tall oak tree to a height below the transitional surface or remove the tree entirely. The tree was located 36 feet southwest of the Final Approach and Takeoff Area (FATO); it penetrated the heliport's Federal Aviation Regulation (FAR) Part 77, 2:1 Transitional Surface by approximately 20 feet.
2. Replace hooded light figures with flush green perimeter lights in accordance with Federal Aviation Administration (FAA) AC 150/5390-2C, Heliport Design, paragraph 216.
3. Mark the FATO in accordance with AC 150-5390-2C figures 2-22 and 2-23.
4. Remove all helicopter parking spot markings, and redesign the heliport parking plan in accordance with AC 150-5390-2C, paragraph 214, table 2-1, and figures 2-17 and 2-18.
only the last of which was really pertinent to the accident.
The distance between pad 1 and the fuel farm was only 24 feet yet presumably the pilots operated quite happily with such small clearances - the distance between pad 1 and pad 2 was 33 feet so the parked aircraft could have been 9 feet closer to pad 2 and still be as far away as Pad 1 was from the fuel farm.
There is scant HF information and no assessment of the cause, and while I know a SMS isn't supposed to apportion blame, if you don't clarify the reason for the accident, you end up chopping down a tree and repainting things in a 'paper-safety' response.