Right there, in front of God and everybody, he spit in her cup? Did other customers see this? Did he at least turn his back to you? I'm skeptical - but getting over that: was he still in front of the register when he did it, or did he wander off into a corner so he could do the deed?

The cameras at Starbucks stores only watch the important parts of the store - the safe, the back where the money is counted, and the registers. If he was smart enough to step out of the view of those cameras, there's no video of it. Whatever, if he's dumb enough to spit in someone's cup where you could see it, he's dumb enough to do it in front of the cameras.

I'd call him on it immediately. Don't let the little old lady consume that. Get his name, get the other guy's name, ask when the manager will next be in. Management is usually in 7-4ish M-F. If you're serious about doing something about this, speak directly to the store manager. Don't deal with the "shift lead on duty," don't deal with the assistant store manager. And if the store manager doesn't deal with the guy properly, get a name/phone number for the store's district manager. If nobody will give you one, call 1-800-STARBUC and go from there.

And don't go back to that Starbucks. However, I've never worked with anyone like that at a Starbucks, so don't let this moron turn you off to Starbucks as a whole. Yeah, I'm a Starbucks employee, and though people like that little old lady really wear me out, I've never done anything like that.

Later,
yasher