I haven't been following it closely but I am guessing the documents from the Select Committee were the closest thing to "compelling evidence"
The Intercept wrote an article about it: https://theintercept.com/2023/07/12/covid-documents-house-re...
It begins as:
House Republicans on the subcommittee probing the origin of the Covid-19 virus appear to have inadvertently released a trove of new documents related to their investigation that shed light on deliberations among the scientists who drafted a key paper in February and March of 2020. The paper, published in Nature Medicine on March 17, 2020, was titled “The Proximal Origin of SARS-CoV-2” and played a leading role in creating a public impression of a scientific consensus that the virus had emerged naturally in a Chinese “wet market.”
The paper was the subject of a hearing on Capitol Hill on Tuesday, which coincided with the release of a report by the subcommittee devoted to the “Proximal Origin” paper. It contains limited screenshots of emails and Slack messages among the authors, laying out its case that the scientists believed one thing in private — that lab escape was likely — while working to produce a paper saying the opposite in public.
The newly exposed documents include full emails and pages of Slack chats that were cropped for the report, exposing the “Proximal Origin” authors’ real-time thinking. According to the metadata in the PDF of the report, it was created using “Acrobat PDFMaker 23 for Word,” indicating that the report was originally drafted as a Word document. Word, however, retains the original image when an image is cropped, as do many other apps. Microsoft’s documentation cautions that “Cropped parts of the picture are not removed from the file, and can potentially be seen by others,” going on to note: “If there is sensitive information in the area you’re cropping out make sure you delete the cropped areas.”
When this Word document was converted to a PDF, the original, uncropped images were likewise carried over. The Intercept was able to extract the original, complete images from the PDF using freely available tools, following the work of a Twitter sleuth.