If data is accidentally destroyed, then there is no crime, as there was no intention to destroy it, and no crime can be proven. A crime occurs only when there is both a guilty act, and a guilty mind (i.e. intention to commit a crime). In either case, any destruction of evidence is known as spoliation.
However, accidental damage can be punished, depending on the context. Like gnasher729 notes, civil cases may view such destruction as evidence that the server contained what the plaintiff has claimed. As the civil court system relied only on a balance of probability to determine fault (as opposed to the criminal system which determines fault when there is no reasonable doubt), the court would likely rule in the plaintiff's favour on that particular issue. The Saskatchewan Court of Appeal ruled the following in Doust vs Schatz SKCA 129, par. 27:
[27] The integrity of the administration of justice in both civil and criminal matters depends in a large part on the honesty of parties and witnesses. Spoliation of relevant documents is a serious matter. Our system of disclosure and production of documents in civil actions contemplates that relevant documents will be preserved and produced in accordance with the requirements of the law... A party is under a duty to preserve what he knows, or reasonably should know, is relevant in an action. The process of discovery of documents in a civil action is central to the conduct of a fair trial and the destruction of relevant documents undermines the prospect of a fair trial.
Provincial evidence rules and civil procedures often deal with the failure to produce documents (electronic or not) on a case by case basis. The §30.08 of the Ontario Rules of Civil Procedure may make any order as is just, including dismissing the evidence altogether, unless the judge gives leave to present that evidence.
In a criminal trial, the issue becomes far more complex. If data was in the possession of the Crown, the court may elect to stay charges if it determines that the defendant may not be able to mount a defence, which would in turn impede the ability to hold a fair trial. There is an example of this in Quebec, although I cannot find any case law in that article. Although there was no intention of spoliation, the fact that it happened holds consequences for other parties, even if no charges are laid on the party that unintentionally mishandled evidence.
In these cases, there always remains a duty to preserve evidence, and to comply with court orders. Like I said above, where there is no intention to do otherwise, no crime is committed.
In cases where there is an intention to destroy, or to interfere with the submission of evidence, electronic or not, then a crime is committed. In these cases, these crimes would be s. 139 - Obstruction of Justice and s. 708(1) - Contempt. In cases where a party destroys data intentionally, whether they are the owner or not, then I would not be surprised to see charges of Mischief (s. 430).
Update: I found this really good paper that heavily looks into evidence spoilation and sanctions that is quite interesting and worth a good read.
