
It is possible. Let me explain. So Hwee-un is the one who woke up in the forest..He goes by the name of Soho in his “new” body. He is the love interest of the original Soho who is currently the Goblin King with the mask. Soho (the Goblin King) was the one who was told by Hwee-un that he hates Soho. When the Goblin king admitted that he is Soho he asked Hwee-un (who’s in a new body), who is he to Soho. I believe Soho (the Goblin King) has a feeling who the new “Soho”(Hwee-un) really is. Because the Goblin King is still very much in love with Hwee-un I do believe there is a misunderstanding and he did not bluntly betray Hwee-un. Hope that helps.

Hweeun has wavy hair and golden eyes when he was human and has golden hair and blue eyes as a goblin.
Soha (the true Soha who is now the King) has straight dark hair and purple eyes, but uses magic to change his hair white and his eyes gold (because golden eyes is a sign that he is King). It's why Soha (the true one) was so surprised to see a human (Hweeun) possess those eyes.
Because the Soho who is now Goblin King appears to still be in love with Hwee-un I am under the impression that perhaps Hwee-un last mortal words of “I curse you. I hate you” had more to do with the intensity of Soho love for him that could have very well distracted Hwee-un in life and battle. I believe there is a misunderstanding. The Soho (Goblin King) who is very much connected to the otherwise “reincarnated” Hwee-un still appears to want to see him and desire him so perhaps he didn’t bluntly betray him, more so his love distracted Hwee-un. Perhaps Hwee-un let his guard down? I am under the impression that he wanted Soho to let him go and hate him back because they had to depart from each other and he wanted Soho to move on.