The right thing to do would be to appeal the case under Section 96 of the Code of Civil Procedure as an appeal can be filed against decrees where cases have been dismissed due to procedural errors. Your wife produced all the documents in court and strictly followed court procedures, which works in your favor. Even though a case is uncontested, courts are expected to carefully go through the evidence. The Supreme Court in Balraj Taneja v. Sunil Madan clarified that justice cannot be thwarted by the absence of one party's participation and that the judges must give a reasoned judgment on the evidence before them.
Additionally, in K.K. Chari v. R.M. Seshadri, it was held that mere procedural lapses should not result in the denial of a fair decision if sufficient evidence is produced by the plaintiff. With this precedent, it appears that the trial court has erred by dismissing the suit without an adequate assessment of the evidence.
Appeal needs to be filed within a period of 90 days from the judgment date as in accordance with the Limitation Act, thus, urgency is necessary. It is here that in the appeal, it would be brought on the notice of your counsel that due to the procedural irregularity, the court wrongly considered the case to pass an unreasonable judgment.
Alternatively, although rarely availed of, one can seek redress by a Review Petition under Order 47 Rule 1 of the CPC, again before the same court if the mistake is patent and palpable on the record. However, appeals offer generally a stronger redress.