Just by framing a comment like this you're taking the person who claims to have broken into the DNC at their word, that they're not releasing selectively to build a narrative.
Of course, my bias in accepting a narrative too easily isn't real evidence that the DNC did not act as allies: there is too much existing (confirmed) evidence corroborating that.
And, as mentioned downthread, the DNC could release documents showing that they did oppo research on HRC as well.