This second golden core elder introduced himself as Daoist Green Viper. Despite his enthusiastic and friendly attitude towards Arthur, Arthur stayed away from him and didn't let the man touch him at all.
He was being cautious because Green Viper's body was toxic and contained highly potent poisons. Many years of experience have made him learn not to make any contact with the people of the Purple Flower sect even if he was looting their corpse.
So he tried to distance himself from physical contact with Green Viper. Green Viper didn't like his reaction, though.
Daoist Pale Shadow, who was watching their interaction from the side, understood why Arthur didn't want to have physical contact with Green Viper and thought that Arthur's behavior was reasonable.