The next contact came in the early 1900's. An escaped convict landed on the island in his haste to flee the Indian authorities that we're chasing him. The Sentinelese did not shoot arrows at HIM, because they we're too busy slitting his throat. The authorities made no attempt to recover his body.
The island then remained untouched for about 60 years until 1964, when someone tried again. A bunch of anthropologists decided they would "win the natives' friendship by friendly gestures and plenty of gifts. So they landed on the beach just out of arrowin' range, and left behind a pig and some toys. They then cheesed it off the island and back onto their boat. They were delighted when the natives approached and accepted the gifts. They were less delighted when the natives STILL fired yet another shitstorm of arrows at their boat, hitting one member of their party in the leg.
What did they do with the gifts? Pigs we're indiginous to the island, and it was known through faraway observation that the Sentinelese ate them all the time. However, rather than doing the same with the gifted one, they SHOT THE PIG AND BURIED IT. They also buried a doll that was among the toys. However, RED buckets were taken with apparent delight, while GREEN ONES WE'RE REJECTED.
10 years later, in 1970, a group of explorers approached the island but again stayed out of range. They did manage to send a care package of fish inland - which we're taken with delight but the Sentinelese continued shouting at the boat and presented their weapons, mock aiming at the contact party and gesturing them to go the fuck away.
When the boat didn't move, women came out of the forest AND HAD A GIANT ORGY WITH ALL THE WARRIORS ON THE BEACH - all in front of the boat. Shit got awkward, so the boat left.
Very few people ever went back after that - but one group actually managed to land, AND be the first ones ever recorded to get inland. They found a native village - but it was completely deserted. They heard noises in the bushes and wisely hightailed it back to their boat before the clock struck arrowing time.
After this, the Indian government made it illegal for anybody to visit North Sentinel Island.
They are defacto free to do whatever the fuck they please.