yes. I agree that Slugborn made a terrible mistake, but he must be seen from his perspective, he likes successful-to-be wizards and witches. But, he might be a weird person, yes. But he had the ability to admit his mistakes and he tried to correct his mistakes, although it took Harry a special potion for that. But still he told him where Tom Riddle's secrets are
We're not denying that, when you're drunk all inhibitions go out of the window, so whatever was stopping Slughorn from telling the truth was immediately lost when he was drunk... we're just saying that all it took was a relaxed atmosphere and some careful coaxing (plus alcohol) to make Slughorn's subconscious take over and allow him to spill it.
i think he felt really bad about telling him that so he tried to hide it but the guilt was on his concience and he wanted to make it better but he didn't know how. so harry got it from him cuz he said that would be the only way to make it better wich was wat he subconcously wanted to do and y he took the job in the first place.