I know that we aren't supposed to get in to legal discussions here, so I'd say check with an attorney, but here are 2 thoughts to ponder:

1. Does the company have a Human Resources Dept? It'd be worth speaking to them about it and documenting the meeting (asking them to document it as well and maybe having them give you a copy of the meeting notes or something to prove you were there).

2. Is your state an "employment at will" state? Some states have the right to fire anyone at any time for any or NO reason... called Employment at will. PA is one. If it is, you may have no recourse...