Wis. Stat. § 751.06
In an appeal in the supreme court, if it appears from the record that the real controversy has not been fully tried, or that it is probable that justice has for any reason miscarried, the court may reverse the judgment or order appealed from, regardless of whether the proper motion or objection appears in the record, and may direct the entry of the proper judgment or remit the case to the trial court for the entry of the proper judgment or for a new trial, and direct the making of such amendments in the pleadings and the adoption of such procedure in that court, not inconsistent with statutes or rules, as are necessary to accomplish the ends of justice.
Wis. Stat. § 751.06
The court may reverse in the interest of justice even though proper motions or objections were not made. A judgment was reversed because the defendant's counsel persisted in asking questions that amounted to testimony on his part and because in arguing to the jury he commented on facts that he had observed. Lorenz v. Wolff, 45 Wis. 2d 407, 173 N.W.2d 129 (1970). A general judgment creditor, having failed to timely appeal from a foreclosure judgment, was not entitled under this section to remand for a factual determination of a real, although perhaps untried, issue affecting the homestead exemption. Anchor Savings & Loan Association v. Week, 62 Wis. 2d 169, 213 N.W.2d 737 (1974). A new trial was necessary because of the prosecution's failure to make full and fair pretrial disclosure to the defendant of exculpatory evidence. State v. Stanislawski, 62 Wis. 2d 730, 216 N.W.2d 8 (1974). Requirements for a new trial upon the ground of newly discovered evidence are discussed. State v. Boyce, 75 Wis. 2d 452, 249 N.W.2d 758 (1977). When a verdict form did not contain a special fact question regarding a major issue of the case, the real issues had not been tried. Schulz v. St. Mary's Hospital, 81 Wis. 2d 638, 260 N.W.2d 783 (1978). Although failure to object at a conference under s. 805.13 to a substantive defect in the verdict constituted waiver, the failure to object did not preclude the court's consideration of the defect under s. 751.06. Clark v. Leisure Vehicles, Inc., 96 Wis. 2d 607, 292 N.W.2d 630 (1980). See also Air Wisconsin, Inc. v. North Central Airlines, Inc., 98 Wis. 2d 301, 296 N.W.2d 749 (1980). When the credibility of a witness was a critical issue, exclusion under s. 906.08(1) of the evidence offered was grounds for discretionary reversal. State v. Cuyler, 110 Wis. 2d 133, 327 N.W.2d 662 (1983). Under the second prong of the discretionary-reversal statute, the "miscarriage of justice" prong, a court would have to conclude that there would be a substantial probability that a different result would be likely on retrial in order to grant a discretionary reversal. State v. Schumacher, 144 Wis. 2d 388, 424 N.W.2d 672 (1988). A new trial may be ordered in either of two ways: 1) whenever the real controversy has not been fully tried; or 2) whenever it is probable that justice has for any reason miscarried. Separate criteria exists for determining each of these two distinct situations. Situations in which the controversy may not have been fully tried have arisen in two factually distinct ways: 1) when the jury was erroneously not given the opportunity to hear important testimony that bore on an important issue of the case; and 2) when the jury had before it evidence not properly admitted which so clouded a crucial issue that it may be fairly said that the real controversy was not fully tried. State v. Hicks, 202 Wis. 2d 150, 549 N.W.2d 435 (1996), 94-2256. State v. Wyss: A new appellate standard for granting new trials in the interest of justice. 1987 WLR 171. A Fearless Search for the Truth No Longer: State v. Henley and Its Destructive Impact on New Trials in the Interest of Justice. Mark. 2012 WLR 1367.