First there was this:
... [Kelly] Wilson filed her lawsuit [against Diz Co.] in March of 2013 claiming that there were distinct similarities between her short film The Snowman and a trailer for the Jennifer Lee and Chris Buck- directed Frozen.
And then came this:
... Federal Judge Vince Chhabria agreed. “The sequence of events in both works, from start to finish, is too parallel to conclude that no reasonable juror could find the works substantially similar.” ...
Because of the judge's non-cooperatino with one of our fine, entertainment conglomerates, Disney twice failed to get the lawsuit tossed out of court. Which ultimately led to this:
... The two sides [Wilson and Disney] have reached a deal. “The Court was advised on June 10, 2015 that the parties have resolved this case,” wrote U.S. District Judge Vince Chhabria in an order filed on Wednesday. “Therefore, it is ORDERED that this case is DISMISSED without prejudice”
The confidential settlement stops an October court date for the civil trial in its tracks, and I'm guessing that the settlement was worth Kelly Wilson's while. Because I'm guessing that the legal minds working for the Walt Disney Company believed it was important to make the lawsuit go away.
Leverage. Based on the above, I would say that's what Kelly Wilson had.
Add On: And an example of less leverage.
In late May, 2015, Royce Mathew, an Altamonte Springs, Florida, resident, filed a complaint with his local FBI office regarding alleged fraud and corruption perpetrated by the Walt Disney Company upon him and the other shareholders in that corporation. ...
And so it goes.