Here is some add'l. info on detrimental reliance for you:

You are the Director of Human Resources for a company. On behalf of the company, and after several rounds of interviews, you offer a job to a prospective employee, with a start date two months away. The employee accepts. Soon thereafter, the company changes its mind, either because it finds a better candidate or because the company hits some hard times and no longer needs the prospective employee’s services. Can you rescind the offer without any consequences? Probably not.

Where an employer hires a prospective employee and then rescinds that offer after the prospective employee has taken steps in reliance upon that offer, the employer may be legally responsible to pay damages to the employee. This apparent loophole in the employment at will doctrine may have significant implications as the economy continues to show signs of a deepening recession and employers are forced to find ways to cut the bottom line.

The legal theory that supports the prospective employee’s claim is called “detrimental reliance.” Pared to its core, the detrimental reliance theory permits a person to file suit for a “broken promise” in certain circumstances. Under this theory, an injured party can assert a claim where (1) a promise was “clear and definite;” (2) it was made with the expectation that the promisee would rely upon it; (3) the promisee relies upon the promise; and (4) the promisee is injured as a result. The detrimental reliance theory is not limited to the employment context, and has been invoked in a wide array of settings, typically when the necessary elements for a binding contract do not exist.