How would the government go about destroying evidence in a defendant's possession? (If you mean "Has the government failed to meet its burden of disclosure reg

How would the government go about destroying evidence in a defendant's possession? (If you mean "Has the government failed to meet its burden of disclosure regarding evidence in its possession:" yes, it occasionally happens. The significant incentive against it is that it's immediate grounds for a mistrial and incredibly embarrassing to a prosecutor's office that has it happen on their watch).