[rdl]

The standard hacks for referrals are:

Call or email, leave a message asking to be called back IFF the candidate was exceptionally strong. Assuming you aren't a competitor, you'll probably get a call back if true. If the guy was meh, it is a nice way to pocket veto.

For when you do employee referrals, if employees are getting pressured by lames to refer them, let them do no-op referrals. Default bring meaningless, and "strong referral" being a real referral. Google, Facebook, etc do this.

[tallanvor]

Any company who wants to avoid a lawsuit will respond to your request whether or not they consider the person to be "strong". And the good ones will contact the ex-employee and inform them that you are trying to get around their reference policy

[rdl]

Not in the case where it is one fairly respected hiring manager calling another in a smallish industry. Not corporate HR (startups, not like HR is more than form filling).

It would be exceedingly difficult to successfully sue someone for failing to return a call or email from a random outsider. Plausible deniability.

This is also one of the cases where being part of a "mafia" is awesome -- you can actually call up and get unvarnished opinions, or at least, cagey "I don't think I would" "That might be difficult" etc.

[huhtenberg]

This is prone to false positives. I never return voicemails that are left by recruiters doing a background check. It's just a single sample point, but I'm sure there are others.

[rprasad]

That is quite honestly, the stupidest "hack" I have ever heard of. People gets dozens or hundreds of emails or calls each day, especially at the manager level. They don't always have the time to respond to each email or call, especially (to them) low priority emails about a former employee.

Your suggestion would basically just screw over any person whose boss had more pressing matters on his plate.