Q:

Dual Employment for At-Will Employment

I'm asking on behalf of my friend.
She has a full-time job at a university, and she worked for a month during summer at another company in a form of an at-will employment. 
There was no formal contract, although she signed a certain document specifying the conditions of employment, which states in itself that it is not a contract.
After she stopped working at the new company and came back to the university, she realized that the signed document stated the condition that she should not receive salary from her original employer (the university) while working at the company. Since she was unaware of this condition, the university had already paid her salary, which potentially brings a dual employment issue.
Since she never singed a contract, it'sBrandon Moye, Laura Mafla, Olivia Fish, and the rest of the Reed Lab for their help with fly husbandry and image processing. Sean Mendez built the original TreadWheel with assistance from the UAB machine shop. Funding for this study was provided by NIH-R01 GM 098856 to LKR and the Undergraduate Creativity and Research Academy at the University of Alabama to KEL and BJW.