The main character (A) is randomly accosted by some guy, who is allegedly working for some kind of organization aiming to make the city greener, on the street to sign his petition with the main character's name and phone number. Later he gets a call from an unknown number that the payment of his loan is due and that he better pay up soon or else he'll have some goons sent over to beat him up (it's obvious that the petitioner is behind this) but the MC refuses and hangs up on him. Later he gets a call from a friend (B) who says that his co-worker ran into the same situation, except that he was gullible and actually paid the amount and asks MC for help in finding out who's behind all this.
Here's the conversation:
B: うちのホストでケンヤって奴がいるんですけど、そいつが偽の借金取りに騙されたらしいんですよ。
A: 偽の借金取り？
B: えぇ。話を聞いてみたらチンピラっぽい格好をしたヤツが「神室町に森！」と言って署名活動をしてたとか。でもそいつ、連絡先どころか許可証すら見せなかったらしいんですよ。そんないかにも怪しい署名にわざわざ名前と住所と、電話番号まで書くなんて・・・間抜けすぎてちょっと呆れちゃいましてホント。まぁ悪いやつじゃないんですけどね。
A: gasps ・・・・・・・・・ (probably because he realizes that he fell for the same scam himself)
B: どうかしました？
A: え、あぁ、いや・・・ずいぶん性質の悪いやつのようだな。
B: そうですよ！ケンヤもこんなアホみたいな詐欺に引っ掛かる奴ですけど真面目に働いてたんです。
The bolded やつ is what confuses me. Which person does it refer to here, the scammer or Kenya? I'd assume the former as 性質が悪い usually refers to a person who, as far as I know, is inherently bad in an evil/selfish kinda way whereas Kenya isn't a bad person according to MC's friend but rather just gullible. I've taken a look at the official translation and the sentence was translated as I just can't believe Kenya fell for that. which does seem more natural given the flow of the conversation but now I'm not sure.
Can 性質の悪い人 be interpreted as somebody who's just stupid/gullible but not evil?
As always many thanks in advance for your help!
