Passing the buck...

So I saw a former subordinate of mine today.  He's looking for a reference, as well as a recommendation.

Now he asked my former boss' boss, and he asked my former boss.  Now he's asking me.  My predecessors passed the buck on this guy because of less-than-stellar job performance.  Now I'm faced with a decision:  Agree to be a reference and paint a glowing portrait of the guy, or agree to be a reference and be tough on him.  I would hate to burn a potential networking contact for the future, but I feel it would be irresponsible of me to simply pass a problem off to another employer.  Were it not for the layoff, he'd have been reassigned or let go.

So I think I'll do the only thing I can do:  Give an honest assessment of my former subordinate's skills and abilities.  I won't trash him, but I can't sing his praises either.

I only hope my own references are as fair to me.