There's a natural alignment of incentives when you're working on the same codebase as someone who actually knows what they're doing. Any mistake you make, they have to fix, and so they have good reasons to see you get up to speed as quickly as possible.
Another good heuristic for online forums and comments: the shorter the comment, the greater the chance that the person actually knows what they're talking about. Experienced people often might throw out a quick correction because it costs them nothing, but have no desire to get into a big debate because their time is more valuable than that.