As for your question, I haven't had a offer rescinded and the only time I have heard of it happening is because of a major issue, such falsifying credentials/degrees.
Then I went to college and in my first semester, the research director offered me a position to develop software for their research projects.
After I left college, I've been working for an advertising agency 1 year now developing more CRUD applications for local companies.
So "real world" experience (in other words besides doing research and my summer internship at a top national laboratory) I've only got 2 1/2 years of experience.
I know a guy 1 year out of school charging $80/hour. Businesses pay for stuff getting done, not experience.
No tech companies, no headquarters of any kind.
The company that offered me a job is a big company (5000 employees) and is among the fastest growing companies in the US, so it would be a huge bummer if I got my job offer rescinded, I just can't stop thinking about it.
I didn't even know there were developer jobs anywhere in the country that pays $12/hr.... but hey, free market right? whatever you are willing to take:)