Yeah, in my experience, Stack overflow answers suffer from subtle errors all the time too. Especially for basic questions -- the people answering and upvoting the answers are inexperienced devs, so they often upvote answers that are either the wrong way to do it (eg. reimplement something that has a very elegant built in way to do), or they just contain bugs (eg. because they mixed up the number of characters vs the number of bytes in a string).

They are still useful, you just have to make sure you understand what you are doing and read the relevant docs before you paste the code.