Dilemma and advice

I have a kid friendship question. Only I've pretty much already answered it in my own mind, so it's not really a question so much as fishing for reassurance.

Here's the deal: there's a kid in Si's class who has called him a couple of times this summer asking to play. He's never gotten through to Si personally; once he (actually, his dad, who was calling for him) talked to me; once he left a message. Si has been informed of these messages and has been nudged to call back, but he has shown zero interest in returning this kid's calls. Negative interest, even.

My normal position on Silas's social life is that I keep out of it. (Which is a separate question in and of itself: how much should I be interfering/ directing/ shaping Si's friendships?)

However, as the message-taker, I feel responsible. Also, I feel bad for the guy in his class. My sense is that he is not well-liked. Rumors get spread about him. All things being equal (when are they ever equal, though?) I think I would nudge Si a little harder about calling him back.

However--and here is where the water gets murky--I have a gut reaction toward this guy, and it is negative. I've been in Si's class. The kid is a little out of control. Also, I get reports like "people don't like X because he gets really mad and kicks people" and "X says he plays Nintendo until 3 a.m. and his parents just let him." Also, his parents: they are divorced, and his dad has clearly remarried a trophy wife. They seem like uncomfortable, dissipated people. This is based solely on gut instinct, meaning on sheer surface prejudices. I don't like that I do this. Nevertheless, it is the data with which I am working.

My charitable instincts (give the poor kid a chance) are at war with my parental instincts, which tell me this kid, however pitiable his home life, is unlikely to be a good influence. He's likely to engage in questionable behaviors in a playdate at his house and need extra supervision at a playdate at our house.

More data: I am myself a few-close-friends sort of person, not an embrace-a-wide-and-diverse-acquaintanceship person. I don't pursue or encourage friendships with women I don't like or don't trust. And I don't feel right pushing my children to do so, either. I try to enforce a rule of kindness, but there is a difference between being breezily polite/ friendly in a neutral location, like school, and inviting someone into your house.

I feel bad. But I'm not going to do it.