Sentence:  This study highlights not only the distortions introduced by legal concerns about the <WSD>co-employment</WSD> doctrine but also the complex relations that can emerge between regular employees and contractors, working side by side and yet separated by employment status, administrative/political, and cultural distance -- in this case, with tragic consequences. 
Meaning of the word marked with <WSD> tags:  A relationship between two or more employers which involves having rights and obligations concerning the same employee for the same work, such as the relationship between a contract agency and one of its clients.