Sorry but I don't think that previous establishments of employment are a good measurement for why someone is leaving or has left OR if they will be a good fit for you.
I worked in retail management for many, many years. I hired some duds. I also hired some stars. After a while I learned when to trust my instincts and what personality-types would be the best fit. I could also tell when someone was just "filling a slot" - looking for a job, not a career. Ditto with the restaurant industry - you know what will work and what won't... you'll probably make mistakes hiring some people and there will be others you'll wanna clone because they're awesome.
People change jobs for many reasons. My generation is probably the worst for that because we're of the Dot Com age - Generation X. We'll change jobs just because there's no casual Friday. Fer Sur.
PS
I base my tips off the trans-fat on a menu.
