"We'll call you back..." Does this mean I didn't get the job?

I had an interview yesterday at a restaurant. I was a little nervous and slipped up on a question. Otherwise the manager was impressed with my experience and availability. At the end of the interview he said that if he finds the "perfect candidate" they would start ASAP. He also made sure he had the right number to contact me, and smiled while saying "Be expecting a call". He had to help some guests at the door so he walked with me, and right before I left I asked if there was a time frame where I'd know if I got the job or not. He wasn't smiling anymore, but didn't seem too irked by the question. All he said was "If I were you, I'd just be expecting one."

So, what do you think?

It just means they have multiple applicants and they're going to evaluate you all. Plus, job people are NEVER on time calling people back. The good news is that they're really pushing the good news your way - they don't have to do that. So that's definitely a plus!

Hexaemeron is right. The never offer you the job on the spot because they want to discuss it among themselves first, plus check your references, Google for you on America's Most Wanted, and so on. Also, they don't want to get your hopes up prematurely. So they always end the interview with "we'll call you" whether it went well or poorly.

"If I were you, I'd just be expecting one." sounds pretty encouraging to me.

Yeah, most employers check you references, your credit history, and if you have a criminal background. A minus in any one of those areas will get you kicked out of consideration these days.