I was reading a manga, and I came across that sentence and I can't understand the use of ばかり, I read some grammar guides but I can't find an explame or explanation that fits this sentence. I understand something like [only people who doesn't want to get involved surely says "I don't know her"]. It's a bit confusing to what it is referring. If someone can parse it, I would be really glad.
The context is that a girl runaway and she left a letter, and she seems to have some problems so she went over to help or something like that. And the main character is reading the letter and he says that while reading it