Legally it often goes to the issue of whether they caused the material to be generated or whether they just obtained and released available info even if illegally obtained. Conspiring to obtain it illegally is a no-no. But getting it afterwards, however, reprehensible has been upheld by the Court as not being illegal- in the New York Times case. Ironically, although the libs have relied on this for years, they try to get Don Trump jr locked up for saying if you have shiite I on Hillary, I want it. You can't have it both ways. You have to demonstrate that the Hillary material would not have been in the third party's hands but for a direct order by Trump Jr. to do something knowingly illegal. Mueller apparently did not get there, despite CNN cheerleaders concluding that he had for months.
No punchline there. I dont know the facts and each case is fact bound and then you have to apply the law. I am not up on all of Assange's "procurement methods." Probably the government is not either, so far.