I knew the pilot. I actually felt sorry for the Lifestyle pilots who ferry pax from POP to Cofresi all day, every day. Must have become quite boring quite quickly.
They were always very courteous in the air. They never bothered anyone, buzzing around at 500ft along the coastline. Their RT was impeccable, they never seemed to let the monotony affect their complacency.
Night VFR is forbidden in most parts of the DR. There are a few corridors. There is one from STI to LRM, but I would never want to attempt that in a single engine aircraft. There are no safe places to put down in the event of an engine failure. It seems that the helo was on this corridor, but not sure which rules he was flying under.
May you rest in peace Roberto and your passengers.