There are two senses of "expect", one about factual expectations (what you think will happen) and one about moral expectations (what you think should happen). There is plenty of efforts from Sanders efforts to impose accountability from very early on for variously ways the DNC seemed to be putting its finger on the scale that Sanders "expected" a fair fight in the second sense, and was prepared to fight to make the fight as fair as possible.
There's zero evidence I can see that Sanders "expected" a fair fight in the first sense, which is what you seem to be suggesting.