Liked would be a wrong word I suppose, but he definitely admired her then, he liked the way he stood for her needs without bothering about the rich man I'm front of her
He had once said that itna confidence sacchai se hi aata hai, he might have changed externally but his heart still had that Om who believed in this, that's why even while taking the phone he replied to Gauri's questions to prove that he was the real owner of the phone
He believed that the girl might be arrogant n irritating but is a strong n truthful girl, hence when he saw the same girl selling herself for money (as he felt seeing her with KT) and Jahnavi Thakurain committed suicide he felt cheated not by Gauri but by his own senses but this Om had now become someone who doesn't want to blame himself so he threw out his frustration on her, still there were some benefit of doubt in his mind when he saw her saving him during train fall, n he saved her from the mob which caused him to lose his deal n brought enimity with KT because he felt that she deserves a fair trail but now he sees that girl happily marrying to KT for money this means she wasn't even worth giving a trial
Probably the thought of his senses betraying him twice for the same girl has made him angry and full of hatred for Gauri