If we were to take Beergate as an example, even if the police conclude that there isn't a case, it won't restore reputation with all so confidence would seem a misjudged position even if there is no wrongdoing.
While it makes no difference to whether there is anything to the case, it's difficult not to see some minor responsibility for this in Labour, and Rayner's hands, in that were this to be Oliver Dowden, I doubt the behaviour from Labour would be any different to the Tories.
I suspect that for any one not completely partisan on this that the case seems small beer, as indeed did Beergate, and possibly involving a more technical breach than any huge evil conspiracy, but again it's hard to think Labour would have taken that approach in any theoretical Tory story.
As already mentioned, the lack of immediate transparency will not help in recovering reputation.