In the general case it's "I believe X based on signs that would imply X correctly, and I happen to be correct that X holds, but I misread the signs I used to come to the conclusion".
I don't think this is rare -- including in the version of my example.
The only reason there's arguing that it's not a "clear cut case" is that I mentioned seeing "symptoms". Ignore the symptoms I mentioned, as they are a red herring, e.g. seeing the mark could cause the belief alone.
Other than that, it's a belief (1), that's justified (2), and true (3) -- while being accidentally justified.
Consider the case of a policeman that things someone is dangerous because they think they seen a gun on them. So they shoot first, and lo and behold, the suspect did have a gun on them -- but what the policeman seen was just a cellphone or something bulky under their jacket.
Or the spouse that thinks their spouse is having an affair because they see a hickey. Their spouse indeed has an affair (and even has a hickey on the other side of the neck), but what their spouse saw was just some small bruise caused by something else.
Or, to stick with the theme, figuring domestic abuse, and the victim suffers that indeed, but your guess is based on a bruise they had from an actual fall.
I don't think this is rare -- including in the version of my example.
The only reason there's arguing that it's not a "clear cut case" is that I mentioned seeing "symptoms". Ignore the symptoms I mentioned, as they are a red herring, e.g. seeing the mark could cause the belief alone.
Other than that, it's a belief (1), that's justified (2), and true (3) -- while being accidentally justified.
Consider the case of a policeman that things someone is dangerous because they think they seen a gun on them. So they shoot first, and lo and behold, the suspect did have a gun on them -- but what the policeman seen was just a cellphone or something bulky under their jacket.
Or the spouse that thinks their spouse is having an affair because they see a hickey. Their spouse indeed has an affair (and even has a hickey on the other side of the neck), but what their spouse saw was just some small bruise caused by something else.
Or, to stick with the theme, figuring domestic abuse, and the victim suffers that indeed, but your guess is based on a bruise they had from an actual fall.